You're in a pretty sucky situation! I've been in a situation like this before. I can tell you first off if you keep pushing, to break your friend up with his/her significant other your only going to create problems! its really hard when you feel like its the right thing to do, but trust me your friend will be upset. Sometimes you just have to let them realize that their significant other is no good for them. Trying to break them up will only create a lot of negative energy between you and your friend, you and your friends significant other, and you and yourself. Unless you really notice something that he/she HAS to know, its not your place to break his/her heart.
