There are just two cases in the marital sex debate:
1. Sex is about emotion and connection. In this case, if the other person isn’t 100% willing, there’s no point. What kind of connection is that? It breeds resentment.
2. It isn’t. Fine, then use your hand. No one cares if that’s not as fun for you: you don’t get to use someone else’s body to masturbate just because it feels better. You just admitted it’s not about emotion or connection.