"Being in love" and "having one-night-stands" doesn't necessarily go hand in hand.
I think her heart has always been loyal to Neal, but I don't think she practiced asceticism, lol. Judging from her comments towards Mary Margaret (before the curse broke) she had a few man, but had bad experiences with them, because apparently some of them were married ect.. and she also claimed that she never got any further than having one-night-stands with them, when Mary told her about the Dr. Whale thingy she had.