Ok this may sound strange, but My penis is too big for my boyfriend to handle and I was curious if there was such a think as a penis stopper or something you can put on the shaft of the penis to control how far in you go?
You need self control... or he can be on top in order to control the depth himself. You possibly could use something like a penis ring or similar device but really...respect his comfort and have some self control and respect and do not enter him so deeply.
Self control would help but I think if you are in the heat of the moment you may go to far. You could use a penis ring as a governor. It also might make it more pleasurable for you if you are vibrating.
Good luck
Good luck