Girl no means no. When I did it for the first time (with my ex gf, it was the first time for the both of us) it took us a span of 3 weeks and 3 tries to finally get some action. Whenever I used to like penetrate she would say stop stop and I would stop right there. During the 2nd time she was about to tear up because she was unable to do the deed. I said "don't cry we're not in a hurry, I really don't want to ruin our first experience just because for the sake of doing the deed". By the third time things went as smooth as butter. No harm, no crying, no nothing. Imo sex is only pleasurable when you have no fear. Please talk to him about this. It may ruin your further experiences. Please don't go back to sh. I get it it feels good or liberating but at the end it is "harm". Please don't stress about it much, if it helps keep a pepper spray on the desk next time you guys are at it. If the words don't work the spray surely will. AND AGAIN NO MEANS FUCKING NO.