Bisexuals aren't greedy. They like people from both camps, what's wrong with that?
I believe homosexuals or lesbians are the more greedy ones. Most of the lesbian relationships (no gay relationships) I know of are pretty...strange, if anything. One of them has both parties completely obsessed over each other and arguments have gone off about jealousy, but they love each other at least. Another I know of is COMPLETELY fucked up. One of them claims they're suicidal, depressed and bipolar (the first is possibly true). A lot of them are really attention seeking. It's, like, 'Look at me, I'm in a same sex relationship!'
Not trying to sound like I'm homophobic. Some of my best friends are bisexual. It's just that whoever says that bisexuals are greedy are wrong.