Sex can never be beneficial to anyone, man or woman, who does not want it. Remember, if you say no and do not want sex and have it anyway, it is very dishonoring and degrading to you and chips away at your self esteem bit by bit. Do not ever allow anyone to convince you to have sex if you do not want to have it. There is a reason it does not feel right to you and that is what you need to focus on, your own feelings, not the feelings of someone who is saying things to force you to do something that is "beneficial" only to him or her.