Kissed Maya Avant, who was in a relationship with Rick Forrester 
Carter Walton came to Los Angeles to visit his adopted brother, Marcus Walton, who had also been adopted by Forrester family patriarch Eric Forrester. Carter met Marcus' wife, Dayzee Leigh, who had long ago helped Maya Avant, wrongly jailed for a crime, give up her baby for adoption. As an attorney, Carter studied the papers and informed Dayzee that the recently freed Maya had a right to know who adopted her baby. Carter, Marcus, and Dayzee soon found out that both Maya's daughter and the adoptive family had died in a car crash.
Carter's legal expertise was in patents and counterfeits, so Marcus' cousin Rick Forrester, who was tackling problems in that area, hired Carter at Forrester Creations. Carter asked Maya out and brought her to the Forrester mansion for a dinner party, noticing that Maya was uncomfortable seeing Rick with his girlfriend, Caroline Spencer. Carter learned from Caroline that Rick and Maya had been interested in each other, and was wary when Caroline asked Carter to pursue Maya so she would forget about Rick.
Carter was also licensed to perform marriages, so he officiated over the nuptials of Liam Spencer and Steffy Forrester, where Carter met Marcus' biological father, Justin Barber. Carter then agreed to model sleepwear in a fundraiser for Caroline's cancer foundation.
An aspiring actor to boot, Carter thrilled to be cast as the lead of web series Room 8; Maya was cast as his leading lady. Carter kept his feelings for Maya in check as his "Lance" innocently romanced Maya's "Scarlett," but Carter was unnerved when the footage was edited to make the interaction seem much steamier. Though he chafed at delivering the increasingly corny dialogue, the new eroticism in the scripts inspired Carter to ask Maya to sleep with him, despite her budding relationship with Rick. Carter was floored when it was revealed that Caroline knew Room 8's producer and had manipulated the show's content in an attempt to get Rick to dump Maya. Carter and Maya eventually reshot the series the way it had originally been written.
Carter and Maya kissed when Rick was a no-show at Room 8's premiere, but went no further; Carter slept on Maya's couch. But when Rick retaliated by sleeping with Caroline, and Maya responded by dumping him, Carter came to Maya with an idea for a Room 8 script: they read it as Lance and Scarlett, but it was really Carter's unique way of proposing to Maya. Carter and Maya made love to celebrate their engagement, though Carter seemed blissfully unaware that Maya was dragging her heels about getting married. In the meantime, Carter officiated at the wedding of Rick and Caroline, and at the aborted wedding of Ridge Forrester and Katie Logan.
When Maya came to Carter with a recording of Oliver Jones, who admitted only dating young Aly Forrester because of her position in the family, Carter reminded Maya that recording someone without consent was illegal and couldn't understand why Maya was so preoccupied with Oliver. But Carter had bigger problems when he learned that Maya had come on to Rick in the Forrester steam room -- Carter broke off his engagement to Maya and was barely civil to her when they ran into each other. Carter felt like he hadn't been enough when Maya went on about how Rick could give her the good life.
Carter tried to stop Maya from telling Rick that she had seen Caroline kissing Ridge, which led to Rick divorcing Caroline and taking Forrester's CEO chair from Ridge. Though Carter was disgusted with Maya, he also tried to be her conscience when she came to him for advice. After an unusually frantic Maya wanted Carter to run a background check on her visiting sister Nicole Avant, Carter learned that Nicole had lied about attending the University of California. Carter overheard Maya and Nicole arguing and found out that Maya was a transgender woman! Carter felt betrayed that Maya had never disclosed her gender identity the entire time they were together, but realized it wasn't his place to tell Rick about it.
Having become friends with Ridge, Carter told Ridge about Maya to keep Ridge from quitting Forrester. Carter sympathized with Rick when Maya's story was leaked to the public; Carter admitted he'd needed time to process Maya's transition as well. When Maya and Rick fought and broke up, Carter convinced Maya to stay with an apologetic Rick. Meanwhile, Carter was on hand to officiate at the weddings of myriad Los Angeles couples.
Carter counseled young Zende Forrester Dominguez, who felt slighted when his girlfriend, Nicole, became a surrogate for Maya and Rick.