Kissed Hope Logan knowing she was engaged to Liam Spencer 
Stole the Hope for the Future Diamond, then planted it on actual jewel thieves to impress Hope 
Punched Liam Spencer 
Romanced Nicole Avant attempting to get incriminating information about Rick Forrester 
Slept next to Steffy Forrester despite her being engaged to Liam 
Wyatt Fuller is the son of jewelry designer Quinn Fuller and Bill Spencer, Jr., with whom Quinn had a long-ago affair; Wyatt grew up believing his father was dead. Wyatt met Hope Logan when she photographed him taking a solar shower at his campground in Big Bear, California; Wyatt impulsively kissed Hope, who had run away and knocked herself unconscious. Though Hope lamented the absence of her on-again-off-again paramour, Liam Spencer, who was working through being deserted by his wife, Steffy Forrester, Wyatt introduced Hope to Quinn, unprepared for the shock when Hope figured out that Bill was Wyatt's father by matching up the identical sword necklaces they wore. Wyatt felt betrayed by Quinn and was furious with Bill for having given his mother money for an abortion.
Wyatt briefly entertained taking both Hope and Spencer Publications from Liam, but soon focused solely on Hope; Wyatt kissed Hope and found Liam's fist in his face. Wyatt was buoyed when Hope decided to incorporate Quinn's accessories into her Hope for the Future (HFTF) fashion line at Forrester Creations, and gladly followed Quinn's order to take Hope to Mexico to secure a rare diamond. Surprised when Quinn sent Hope the video tribute Liam had made for Steffy, Wyatt used the rift to propose to Hope himself. To further endear himself to Hope, Wyatt pocketed the diamond and placed it on actual jewel thieves; Wyatt was deemed a hero by the public and by Hope.
Wyatt began dating Hope when she dumped Liam, whom she'd spied in heavy conversation with Steffy on their wedding day. Wyatt made love to Hope for the first time on a beach camping trip, which was interrupted by Liam, who provided security footage of Wyatt "stealing" the diamond. Wyatt was dismayed when Hope left him standing on the beach, but later, after Hope took him back, Wyatt's theft was buried by Forrester Creations to prevent a media scandal.
Wyatt wanted to honor the late Forrester matriarch Stephanie Forrester by tying her personal jewelry into HFTF, but Stephanie's granddaughter, Aly Forrester, who had a history of mental illness stemming from the violent childhood death of her mother, loudly objected. Wyatt dismissed Aly's claims that he was corrupting the message of purity Hope had layered into HFTF and earned a slap in the face for bragging to Aly that he had slept with Hope. Indeed, Wyatt and Hope were shocked when Aly caught them in bed and threw a tantrum.
Wyatt was disappointed when it turned out Hope wasn't pregnant, and more so when Hope agreed to date both Spencer brothers. After Quinn took a picture of herself in bed with Bill and showed it to Bill's rival, Ridge Forrester, who wanted to keep his ex-wife, Brooke Logan, from marrying Bill, which resulted in Ridge falling from a helicopter and sustaining brain damage, Wyatt punched Liam for calling Quinn a "vile, manipulative, evil bitch." Wyatt lost both Hope, who chose Liam, and his position at Forrester Creations due to Quinn's misdeeds; Wyatt turned his back on his mother.
Wyatt couldn't believe it when Liam reported that Quinn had threatened to kill Liam and Hope. When Wyatt learned from Quinn's new boyfriend, Deacon Sharpe, that Quinn had expressed the same desire to him, Wyatt ran to Liam's house and barely stopped Quinn from impaling Liam with a sword. Wyatt and Liam bonded over the ordeal, and later Wyatt received a text from Quinn in which she said she had checked into a psychiatric hospital.
Wyatt inherited the HFTF diamond from its owner, Ricardo Montemayor, and publicly presented it to Hope. But when a detective told Wyatt that Ricardo had been murdered, Wyatt briefly wondered if Quinn had been responsible. Rehired by Forrester as a liaison for new jewelry designer Ivy Forrester, Wyatt flew to Paris with Hope, who had told Liam to meet her by the Eiffel Tower to get married. When Liam didn't show, Wyatt convinced Hope to marry him in Monte Carlo instead. Wyatt was sure Hope would leave him when they found out that the only reason Liam was late was because Quinn had pushed Ivy into the River Seine knowing Liam would rescue Ivy; instead, Wyatt was surprised with the news that Hope was carrying his baby.
In Amsterdam on business, Wyatt arranged a romantic boat ride for new couple Liam and Ivy, which upset Hope; Wyatt told Hope she couldn't have both Spencer brothers. Later, Wyatt felt torn between Hope and Quinn, who were arguing because Hope didn't want Quinn anywhere near her child. Wyatt debated Hope's plea for a restraining order and came under fire after Hope lost their baby falling down the stairs while trying to get away from Quinn; knowing Hope blamed him, Wyatt could only watch as Hope left on an extended trip to Milan, Italy. Wyatt went to Milan to plead his case and came back with a divorce, while tyrannical new CEO Rick Forrester fired Wyatt for being out of the office so long.
Hearing from Liam how Rick was mistreating everyone at Forrester, Wyatt teamed with Liam, who wanted to force Rick out; Wyatt sweet-talked Rick into giving him his job back so he could keep his eye open at the company. Meanwhile, Wyatt frowned on Quinn's relationship with Deacon, knowing Deacon still had a thing for Hope's mother, Brooke Logan; Wyatt overheard Deacon telling Brooke he'd reunite with her if he wasn't engaged to Quinn, so Wyatt went straight to Quinn with the news. After Quinn and Deacon worked things out between them, Wyatt was the only guest at their wedding, aside from Hope, who had been brought in by Brooke via video call in an unsuccessful attempt to stop the ceremony.
Sensing there was a secret surrounding Rick's mistress, Maya Avant, Wyatt romanced Maya's inexperienced little sister, Nicole Avant, to get information out of her. Wyatt genuinely liked Nicole, but worked on her until she admitted that Maya was transgender. As Wyatt and Liam deliberated over what to do with the revelation, publishing magnate Bill got wind of it and splashed it across his media platforms against the Spencer brothers' objections. Wyatt understood when Nicole declared she'd never trust him again.
Wyatt took an interest in Steffy, who had returned to oust Rick by combining stock with Ridge and Liam. Although Steffy wanted to reunite with Liam, Wyatt laid on the charm and kissed Steffy. After both Wyatt and Ivy found themselves alone, they kissed and began their own relationship. But Aly, who had regressed and targeted Steffy and Maya, died in a violent confrontation with Steffy; Wyatt was incredulous when Ivy showed him footage in which Steffy appeared to hit Aly in the head with a tire iron. Siding with Ivy, who felt she and Wyatt had been marginalized by their families, Wyatt supported Ivy when she used her video to blackmail a modeling gig out of Steffy.
Soon, Wyatt thought better of it and helped persuade Ivy to delete the video, after which Steffy fired Ivy. Wyatt went to Bill with a request to bankroll a new fashion house for him and Ivy and was angry when Bill declined. Seeing Ivy's embarrassment when Steffy only brought Ivy back to model lingerie, Wyatt encouraged Ivy to be fearless and shucked his own clothes to help Ivy get comfortable. But Wyatt felt bad for pushing Ivy to do something she wasn't comfortable with and told Ivy he loved her.
Wyatt didn't like it when Steffy's brother, Thomas Forrester, began openly flirting with Ivy. Wyatt seemed oblivious to Ivy's increasing distance and refused to believe it when Steffy reported that Ivy had kissed Thomas. Wyatt walked out when Ivy confirmed it but rushed to Ivy's side after she was electrocuted following a scuffle with Steffy. Wyatt and Thomas blamed each other for Ivy's condition; Wyatt talked Ivy out of having Steffy arrested for violating her restraining order, then bought a ring for Ivy. But Wyatt's proposal was interrupted by Quinn, who overheard Ivy telling Liam she wanted him back. Wyatt sent Ivy packing and cuddled Steffy in bed while Liam escorted Ivy back to Australia.
After Liam sent Steffy text messages ending their relationship, Wyatt wanted Steffy to move on with him and kissed her at the beach. Knowing Steffy hadn't ridden a motorcycle since she fell off and lost a baby, Wyatt bought Steffy a new bike and encouraged her to get back on. Wyatt continued wooing a resistant Steffy and asked her to marry him; she ultimately agreed. Wyatt was further amazed when Bill gave him Liam's job at Spencer; Wyatt began training under Bill.
Wyatt was thrown when Charlie presented him with security footage that showed Quinn driving off with Liam, who fainted and hit his head in the parking lot. Wyatt took Quinn for her word when she insisted that Liam had come to and taken himself to the hospital before leaving on an extended trip. With Bill as his best man, Wyatt married Steffy on the beach, though Wyatt was disappointed that Quinn hadn't brought the new beau Quinn kept talking about. When Wyatt surprised Quinn at her cabin, he found her kissing an amnesiac Liam, who had been told Quinn was his wife. Wyatt helped Liam lock Quinn in a closet and brought Liam to Steffy, later becoming combative when Liam, whose memory was returning, insisted he wanted Steffy back.
Wyatt felt terrible for what his mother had put Liam through, but campaigned for Liam to let Steffy go. However, Wyatt soon received a text from Steffy with a plea to call the police on the fugitive Quinn, who had arrived on their doorstep. Wyatt watched as Liam told the officers to take the unusually repentant Quinn away, then implored Liam to not press charges, feeling that Quinn would revert to her cold-hearted self in prison. After Quinn was released, Wyatt clashed with Steffy, who didn't want his mother anywhere near them.
Wyatt received a shock when an intruder in Liam's home turned out to be Reverend Rydell, who had officiated at Wyatt's wedding to Steffy. Wyatt breathed a sigh of relief when his marriage turned out be valid; later, Wyatt opposed Liam's idea to create a charitable foundation at Spencer Publications and lobbied for Steffy to become the face of its social media.