B.I.L.B.: Stealing best friends' girl/boyfriends

First let’s talk about the movie. I think that Jess didn’t steal the other girl’s friend (Jules’s) because, in the first place they weren’t in a couple, so it isn’t considered as stealing. It would only be considered stealing if they made a pact involving not going out with him, but I doubt thats the case. Now, what would I do? Stealing you friends girlfriend’s just wrong I wouldn’t even try it, that can easily destroy any friendship.

Manuel