So what was her intent? It wasn't to do anything with his mom but she did so who cares about the intent?
"My best friend asked me to not do anything with his mom, so I left alone with her, left him alone in the shop and fucked her because she didn't know if it's gonna feel right and it got a bit out of hand" Come on, you can do better than that...
And I know that the scene changed but let's be honest, it's the same thing, the MC just arrives like 10 minutes early.
And on top of that like many people said, I still wouldn't like her even if this whole scenario didn't happen because of the other annoying things she does.