We have the opposite experience. He lasts a lot longer since regular black sex has loosened me up. I fit them well but he says he can barely feel me now. But that's a good thing. He doesn't have to worry about cumming too soon so he touches me a lot more, we make more eye contact, talk more during sex. It's improved the intimacy between us. Sometimes ejaculation can get in the way and that's not a problem for us now. We both like it better this way. I feel a little guilty that he seldom cums but he insists he wouldn't want it any other way.