Keith Anderson worked at Malibu hotspot the Bikini Bar with bartender Irving "Sly" Donovan. Keith met customers Thorne Forrester, his estranged wife, Macy Alexander, and Spencer Publications honcho Karen Spencer, who were caught up in a love triangle together. As Thorne was leaning toward Karen, Keith encouraged Sly's interest in Macy; after Sly wrote Macy a poem that she laughed at, Keith wrote more passionate prose for him to give Macy that did the trick. Keith began falling for Macy himself, but didn't dare tell her, especially as she was getting involved with Sly.

Keith worried when it seemed like Macy was drinking too much, and took her home one night after she'd thrown up in the bathroom at Bikini. Keith innocently put Macy to bed, then got stuck in her room when her mother, Sally Spectra, came home with her boyfriend, Jack Hamilton. Keith tried to sneak out but was caught by Sally and desperately tried to explain his presence; Keith was relieved when Sally believed him. Keith tried to convince Thorne to do something about Macy's drinking, then warned Macy that Sly was moving too fast after he heard they'd made love. Keith sent Macy flowers and another poem anonymously, which prompted Sly to threaten Keith's job.

Keith received a visit from his aunt, Ruthanne Owens, who had once been homeless on the streets with an amnesiac Stephanie Forrester, the co-founder of fashion design house Forrester Creations. Keith lamented to his aunt about his unrequited love for Macy, then gave her an update on his little brother, Kevin Anderson, who shared an apartment with him. Keith let Kevin bus tables without Sly's permission, which backfired when Kevin bumped into a drunken Macy and dropped his tray of glasses. Keith asked Sly to cut Kevin some slack because he was mentally disabled, and felt disappointed when Sly continually refused to hire Kevin.

Keith watched Macy descending into alcoholism; when his efforts to help her stop drinking failed, Keith went to Sally and suggested they do an intervention on Macy, which only made Macy resentful. Keith accused Sly of enabling Macy by giving her drinks; when a very drunk Macy wandered off by herself, Keith told Thorne what was happening, leading Thorne to find Macy passed out in an alley. Keith was glad when Macy resolved she'd get sober, but worried when she planned on doing it on her own instead of getting into treatment or going to Alcoholics Anonymous meetings.

Keith kept trying to explain to Sly that Kevin was no different than anybody else. One night after closing, Keith and Sly were threatened by an armed robber; Keith was impressed when Kevin subdued the thief, and when a grateful Sly gave Kevin the busboy job he'd been longing for. At a party celebrating Macy's sobriety, Keith wondered if Macy was still drinking and why Kevin was suddenly acting so strangely. Keith soon found out a drunken Macy had driven off with Kevin, who had seen Macy drinking; Keith visited Kevin and Macy in the hospital after she crashed her car. Keith held his breath as it seemed for a while Kevin wasn't going to pull through, but when Kevin did, Keith accepted Macy's profuse apologies for hurting his brother. Keith was surprised when Sly told the newly-determined Macy that Keith had written her all the lovely poems; Keith was touched when Macy thanked him and said she owed Keith her life.

When business at the Bikini dried up because Macy had stopped singing there, Keith and Kevin found themselves out of work, as Sly was forced by his boss to let the brothers go. But Keith couldn't thank Macy enough when she talked to Anthony Armando, the designer at her mother's company, Spectra Fashions; Keith and Kevin were both hired on as assistants to Anthony.

Keith continued to write Macy love poems but again lost a chance with her when she started seeing Anthony. Keith agreed when Anthony asked him to produce his designs for bathing suits that became transparent when wet; knowing that Anthony planned to have Macy and Karen wear them in the hot tub on a double date with him and Karen's new boyfriend, Connor Davis, Keith made transparent trunks for Anthony and Connor instead, who literally found themselves with their pants down when they got wet. Keith was last seen with Kevin at Connor's wedding to Karen, where Karen declared she had lied about being pregnant to teach Connor a lesson about having unprotected sex with her; Keith has not been seen nor mentioned since 1994.