I go along with sex for my partner sometimes when Im not in the mood because they are, and I want to please them because they are my partner?

Rape is technically sex commited when one partner is not consenting. Someone said this involves 'actively resisting', I would argue you can have lack of consent without that. However, you didnt sound like your partner is pushing? Does the other person know you don't want sex? or are they pressuring you into it? They can only know you really don't want if you tell them. I think you need to increase communication about this to come to a solution.