<human>: I've been having sex and maintaining a close-to-a-relationship lifestyle with a girl that happens to have a boyfriend.
She claims that she has a open relationship but she lies to her boyfriend about me (he suspects it, a lot).
We have become closer and closer everyday and we would most likely dating if she wasn't on a relationship.
The thing is, why is she doing this? She actually likes me in a deeper way than just plain sex.
We live +/- 125 miles apart but we scheduled a whole week to visit me in a month and two weeks in the summer (plus a couple of trips by me for just the weekends).
Is this normal?

Give me a shortened version of the text
<bot>: She has a boyfriend and she's having sex with me. She says she's in a open relationship but lies to her boyfriend about me. What the hell is going on?