<human>: Dear reddit, before we begin I would like to state that I know what I am currently doing is scummy and wrong, but I am caught up in the situation and trying to get out of it which is why I have come to you.

   I have been dating my longtime girlfriend for about 2.5 years and she is the coolest person I know. We get along great, we laugh and have fun, and she is my best friend. She is also the first and only person I have ever had sex with until recently(we'll get to that in a second). Unfortunately, she just doesn't do it for me. I have a very hard time getting turned on, and sex is mediocre at best. I usually feel more satisfied when I take care of myself. 

   Now recently I ran into a girl that I went to high school with who I used to have the biggest crush on. I could tell she was interested, and asked if I wanted to catch up sometime so I said yes.  We ended up talking and hanging out a few times, and eventually we ended up having sex.  Now this sex was amazing, the best I've ever had. It was totally different from anything I've ever experienced. I'm talking about hours on end sex.  However, this girl isn't really my type.  She isn't into anything I'm into and we don't really get along very well if we get too deep into conversation.

   I feel like a scumbag, but I can't help but keep going back to her for more sex.  We basically have a silent agreement that neither of us want a relationship, but the sex is so good that we continue to use one another. 

   What should I do? Should I dump my best friend and girl of 2+ years because I get nothing out of the sex? Should I tell my girlfriend about what has happened and try to make things right?  Should I drop them both and try to find someone that satisfies all my needs?

Can you succinctly summarize the text in 1-3 sentences?
<bot>: I have a best friend I've dated for years that is bad in bed and a girl I don't like that is amazing in the sack. What should I do?