I want to cheat

Listen I don’t want judgement and let me explain myself. I would never cheat on my boyfriend I love him a lot but sadly he’s one of those guys who is immature still and isn’t a very open feeling kind of person. I’ve caught him in lies and he gets upset because I don’t trust him. I live with him so trust me if you had to deal with stuff I do you’d think I was raising a toddler. This morning a old fling hit me up we were just hook up buddies and he was very very very nice and good in bed. ( my boyfriend and I haven’t had sex in months cause he just doesn’t want to and thinks it’s messy). (He’s not cheating trust me he literally has no chance to). I keep getting turned on to the thought of the old fling and I hooking up again. It’s been so long and I remember him being the best I’ve had. I’m never going to cheat on my boyfriend I already shot the guy down. I just need help I can’t take the no sex anymore. What should I do to get my boyfriend to sleep with me again?