He didn't use her did he?! Ahh I will transport myself into your story only to knock him over the head with a lamp or something. Gah. In the beginning, I couldn't get over the feeling that he was using her, and your last sentence didn't help. This is pure torture..
Author's response
if he was using her they would have had sex. Patrick is just still not sure he should be with her--for a few reasons. I don't know if you've noticed but Molly isn't the most stable individual sometimes. And Patrick is pretty convinced the band will leave him living in his parents house making no money for the rest of his life and he knows how Molly's father thinks. So he's nervous about being with her.