Shes stopping me from going and asking him out!?

I like this guy, lets call him connor. Hes been my friend for a while and he was dating my ex best friend, they just broke up and im starting to fall for connor, hes cute, hilarious, charming, and really really nice he makes me feel priceless! I cant stop thinking about him he has blond hair with dimples and freckles he always lets me in on his 'guyish' jokes that are pretty gross sometimes but im pretty chill and i just laugh. Today i was walking and he waited for me and held the door open even when i was still like a minute away :) i really like him and i want to tell him. Problem is, my ex best friend is a total ***** and she would be PISSED if i liked him because she still likes him a little bit ( he dumped her cause she cheated on him.) but i would go nuts if he asked me out but she would ruin it! Help meee!!!!!