feel used??

Jessica

so me and my bf are in a long distance relationship.he's in the navy and he's currently stationed in San Diego while I'm up in LA.Ever since we started having sex I feel like it's all he's going for every time he's up here to see me.He tells me all the time that I can tell him no if I don't want to and that he won't care.But I feel bad about it after all we rarely see each other and he just returned from being over seas almost a month and a half.Even though he always asks me if I'm okay with it and I tell him I'm okay with it,I just end up feeling used by the end of it.should I mention this to him or should I just continue with how it currently is.