Many like BP, feminists, etc. will say along the lines of "women are not sex slaves that are required to give sex to their husbands". And I've noticed basically two things here.

First, intimacy is just reduced to getting a nut. Which is very short sighted, because if your significant other is not willing to do the most special thing a couple can do together, with you, it indicates a bigger problem. Its more analogous to say "your partner is not required to reciprocate love", and when you say that out loud, you realize how silly that sounds, and how it sounds more like emotional abuse. If you go to the deadbedrooms sub for example, you can very clearly see how abusive it really is, even many examples of women not getting intimacy from their male partners.

Second, socially it used to be the rule that sex was expected in marriage. A marriage contract was quite literally an agreement that each party would provide intimacy to each other and take care of each other. But our society has basically gotten rid of that, a man is not required to provide for his wife either. And so if we've stripped all these rights and responsibilities in marriage and relationships, where you're no longer entitled to sex, love, financial provision, etc., then why are other things like faithfulness still expected? Theres the old saying, if he's not getting it at home, he'll find it elsewhere.

If you're saying each partner is not required to give love and intimacy, then what even is the point of a relationship anymore?