Really?
im not sure if that is sarcastic or, if you genuinely dont know, but, ya man, if im not mistaken its, MDMA or better known as ecstasy which is used to turn you into a ball of horny, while making you not wanna slow down. google it. idk where the term molly came from, but then again drugs get hundreds of different names, so who knows.
EDIT:well apparently im wrong lol, just a bottle of water, how i was supposed to know that, idk, ive never heard of it before.
here ya go, for the blind like myself.
http://www.mollywater.com/I'd rather believe she is horny.