<human>: I'm 22(m) and I've been with my girlfriend (21/f) for almost 4 years. Really good relationship overall and breaking up is not an option. GF is 15 weeks pregnant and we are keeping the baby. Marriage is only a matter of when. Our relationship is very serious and I love my GF so much. 

A couple weeks ago I made a terrible decision and kind of/sort of cheated on her. Didn't have sex with the other girl (18/f) but fooled around. I called things off before we could hook up. I intended on just fully cutting out the other girl (Catherine) from my life but that has proven to be really hard.

I'm basically infatuated with her and I feel shitty for feeling this way but I've been almost regretting not having sex with her. We texted and she sent me some nudes a couple days which has just rekindled my desire for her. I feel like a mega-scumbag for this. I don't know how to get Catherine out of my head. I don't want to be the asshole who cheats on his pregnant girlfriend. 

Coming clean to my girlfriend about what happened before or the sexting isn't an option. I just need advice on how to stop feeling this way.

Can you provide a brief overview of the text?
<bot>: I can't get rid of feelings I have for another girl that I kind of cheated on my GF with. Need help