Drama.
My sister in law is gay and all I ever hear from her about her relationships and her friends relationships is drama. I used to go to gay bars with her and all I ever saw was drama. I have a lot of gay friends and it's always drama. It's really not even a lesbian thing. It's gay culture in general.
I think it's what happens when you really can't legally commit. Many of them are basically eternally in relationships that resemble late teen or early twenty relationships for heterosexuals because they can never truly move to that "next level" we can.