How to tell if your girlfriend is a lesbian. Sometimes people will give you clues in their conversations. You may not get a straight answer no pun intendedbut maybe you'll gain some insight. Don't fret, my confused little lez. But if you can't stomach going down on her, you're not a lesbian. Trust me, it has nothing to do with the way the girl dresses. Latest In Relationships. To say you're a lesbian but you don't to perform oral is like saying you're heterosexual and hate the dick. But then again, that is not a sure way to tell if someone is lesbian or not. I can't help but feel that she could be latently bisexual even though she said she did it just to see. She is always commenting on their bodies and how well "that woman" looks. The girl just wanted to reap the lesbian chivalry perks, without having to have sex with her. The straight best friend toys with the lesbian's heart by saying, "Maybe there's a chance one day, " because she enjoys the perks of her bestie's crush.