From UrbanDictionary.com
LESBRO
1. A man who has more friendships with lesbians than other women or men. ant. fag hag
Use: Wow, David sure does hang out with a whole lot of lesbians, he’s becoming a lesbro.
2. A man who befriends lesbians with the intent to seduce them.
Use: Steve is such a lesbro. He doesn’t have a chance with those women.
3. two lesbians who are just friends
Use: “Are Sarah and Liz dating? They are always together!” “Nope — they’re just lesbros.”