Let’s try again. How would you feel?: Added details

I think my boyfriend might be cheating. I tried to explain earlier but left out some details and everyone tried to attack me for it, so here’s why. I think he jerks off in bed while I SLEEP and then when he thinks I’m awake or waking up will stop what he is doing until I stop moving or whatever. I think that is really important and something I should’ve mentioned earlier to make myself look less insane. I wouldn’t mind if I knew and it wasn’t like this weird thing that every time I begin to wake up or start falling again asleep it goes on/ stops you know.. and one of the main questions was “how could he be cheating in bed with you” like people don’t cheat online all the time?? Like is it really that hard to be flirting and sending pictures with someone secretly? Basically what I’m asking is if he’s doing this would you care that your significant other seemed to be doing so behind your back right next to you?

UPDATE: Good morning ladies thank you for all the feedback. I didn’t ask because I feared he would think I was weird for asking out of the blue if he does that while I slept. Our sex life is good. We are pretty on top of it ;). Anywho we talked and he admitted to doing it in the past but said he hadn’t currently so I believe him and that’s all I wanted to know.