Girlfriend has me by heart but side chick has me by ****?

I love my girlfriend, she’s amazing, but I always had my doubts a bit since she was still living with her baby daddy and I heard things and saw things. Overall I love her. I have this other girl who is also very great, the thing is I want to let her go now since I have a girlfriend but damn the sex is so good. She makes me tingle all over and it’s hard to stay away. I’ve tried so many times to let her go but she’s addictive. I want to be a good boyfriend and change but it’s difficult when you have such an amazing sexual connection with someone like that. Sex with my girlfriend is great too but it’s not mind blowing (I sound like a dick, I know). What should I do to change and ways on how I can just stick to my girlfriend. My side doesn’t know I’m taken.
Girlfriend has me by heart but side chick has me by ****?
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