well you can not unless you make the guy look bad
Break up with her she cheated on u
well it's ok for a guy to break up with his girlfriend for a another girl but it's not ok for the girl to go out with a another guy while dating her boyfriend
Wait until they break up, or find another guy.
First you tell her what you saw or herd and then you need to break up because if she sees something in another guy then she's not your girl. so i say break up.
How trustworthy is he? An unfaithful relationship is never a good one.
They think if they break up first they feel like the bigger person and try to empress his friend or they wanna take a break or liking another girl.
You cannot. Unless they break up.
break up with the guy/girl
Tell him or her that your not feeling sparks and say your just not my guy or girl. Be sure to include "your a great guy [or girl], ""But your just not right for me." Take the break-up slow.
either move on or wait. that is the best advise you'll find anywhere. don't break them up unless you want to fight a girl over the guy.
Look for another girl or you could wait for something bad to happen between the two to break them up then the girl would need a shoulder to cry on
well it deppends on the girl. My boyfriend was that guy and now we have been dating for a year