sounds like you are taking this personally.. as it really does have nothing to do with you.. what if you asked him and she goes "you smell." 1. that wont make you feel better 2. Its not because you smell but because of how HE FEELS...
You want closure.. beleive me i understand.. and i would try to get some but I would wait until you are not so emotional about it. But remember this, closure is a hollywood term and doesnt exist and usually leaves you with more questions... If you do ask him make sure you speak your mind and get any answers you are looking for.. it doesnt mean hes being truthful but at this point its the best you can do.
Is it possible he cheated on you or found someone else?
Remember this.. IT HAS NOTHING TO DO WITH YOU! You can replay all these options in your mind of "mayeb if i did this and not that." Youll go crazy thinking about them.... and im being hypocritical because i do this constantly, but I do know that it is unhealthy and WONT CHANGE A THING.