So I've falling for my best friends ex boyfrend and they were pretty serious... serious as in getting married... but called it quits and its been over a year for them but now I'm falling for him and he knows it... so what do I do? Should I try to pursue "us" into something or not...

The first thing you should do is let your friend know where you stand, as well as the feelings you have for him.

With friends there are boundaries, but when it comes to the relationship ending for good, and a years time has passed, I think they should have moved on. Maybe not completely, but If your friend cares about you, she'll understand.

You have to live with yourself. If you have no sense of guilt or feel that this is acceptable to do to a friend,follow your conscience.

If you are willing to hurt your friend and possibly destroy the friendship over a guy,than go for it.

Friends,true friends are rare but guys come and go.