Any work with a predominantly gay male cast will always feature a single lesbian or lesbian couple. It doesn't matter how tenuous their ties with the boys are (usually the main character's best friend and her partner), or if they integrate with the main cast at all. As with any token, they're not there to actually add to the story, but to keep people from complaining that it's not inclusive enough (after all, an all-gay-male cast is still an all-male cast). It's not even guaranteed that they'll pass The Bechdel Test. And you can bet your next paycheck that their plot will involve having children in some way, since All Lesbians Want Kids.
It's not that having lesbian characters is a problem itself, but when a story is centered around gay men, the token lesbian often feels like an obligation more than anything else, and at worst becomes an afterthought who isn't given nearly as much attention and development as the men in the story. The Beard and the Fag Hag can be related tropes if her sole purpose in life is adding a woman to the main cast.
Please note that this is a very specific trope. If the ladies are the only same-gender couple shown, then they're token gays. If the work features couples of all stripes, then they're simply part of the bigger picture. This trope is about those lesbians arbitrarily thrown into a work about the lives of gay men. Related to The Smurfette Principle.
- Chelsea Boys has this, nearly, with Ricki and Lucie. They're there, they're lesbians, and they ask the lead male to be the father of their baby. But the comic also has Annie, who gets a decent amount of page time as Sky's lesbian friend from school.
- Dykes to Watch Out For has a rare inversion with Carlos, the male role model/babysitter for Toni and Clarice's son Raffi. Later on, there was Gerald, a gay female-to-male transsexual Lois developed a crush on.
- The Broken Hearts Club: A Romantic Comedy is primarily about a group of gay male friends, but Dennis' sister Anne and her partner Leslie have a significant subplot where they're trying to have a baby and want him to impregnate Leslie so that their child is biologically related to both of them.
- Muffler in Another Gay Movie.
- The stage technician in The Producers.
- Anne Kronenberg, Harvey Milk's campaign manager in Milk. Not just token lesbian, but also token female; she is the only female character in the film with more than four speaking lines.
- Patrick-Ian Polk's film The Skinny has a main cast of four gay men and one lesbian.
- Zig-zagged in Pride (2014). Steph is initially the sole lesbian in LGSM (Lesbians and Gays Support the Miners), but she's later joined by a female couple...who eventually leave the group to start their own that's all queer women. However, Steph opts to remain in LGSM as she was already friends with the men in the group (also preventing the group's name from becoming an Artifact Title).
- Melanie and Lindsay in Queer as Folk. Lindsay has been Brian's friend for years, and Brian and Michael are the fathers of their two children.
- Australian comedy program Outland features four white gay men and a lone Aboriginal Australian lesbian who also uses a wheelchair. The fifth of the six episodes basically serves to highlight how separate she feels from the group.
- Never Wipe Tears Without Gloves has two lesbian characters who appear in the third episode.
- Parodied on Will & Grace with the fictional Gay network Out TV (not to be confused with the real life network OUTtv) which featured a bumper of several attractive gay men huddling together and a single woman waving to the camera from a different set.
- Estelle in The Normal Heart.
- Kelli and Dawn in World of Fizz.
- Trish, Nick's babymomma from his younger days in Troy. Her new fiancee is an afterthought at best.
- Rick & Steve: The Happiest Gay Couple in All the World:
- Averted with Kirsten and Dana, as they are fairly prominent on the show. However, they still fall victim to the All Lesbians Want Kids storyline, albeit in several unexpected ways.
- After some Character Development from Kirsten and Dana, the show introduced Ebony and Ivory, a couple so stilted and politically correct they made Kirsten and Dana look laid back by comparison.