It sounds like you're shallow, encouraging these guys to hit on you to stroke your own ego, and that you're doing a very poor job of defending your boyfriend.
They're not friends, they're guys who want to **** you but haven't yet. They don't respect that you're in a relationship, and they're all 3 trying to weasel their way into your pants at the expense of their mutual friend.
They're not good people, and that should have been a pretty big red flag for you.
But of course, you're just secretly pining away for another guy and don't have the moral integrity to cut your current boyfriend loose to find someone better than you who actually cares about him. You're keeping him around in hopes the other guy makes a move, and if he doesn't well you've got the current man as your backup bitch.
"Well, then," the Cat went on, "you see a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad."