@jane6564,
Because one person (or thing) cannot satisfy every need we ever have.
Yes, he "needs" more than you can give. Every person in the world needs more than just one person can give them. If it wasn't this, it would be something else. You can't fill the space he reserves for his "guy time" with his friends and you don't want to. But for some reason, women just get so hung up on sex.
It's like reading. Or writing. Or singing. Or crafting. Or restoring. Those are things people enjoy that fill a need. People don't HAVE to do any of those things but they enjoy it so they do. Fishing isn't going to fill the desire I have to read. Having sex with you fulfills many needs and desires he has (maybe all), except one. Simple and unstressful release. Masturbation.
Your husband is looking for a release of his own without the pressure of making you happy. That is not wrong. What this says to me is that he loves you enough to want to make you happy when you do have sex. He isn't replacing anything.
This has nothing at all to do with you.
Read that again.
This has nothing at all to do with you.
He doesn't love you less or want you less. Or expect you to be a porn star. He is doing this because it makes him happy on his own time.
If he was masturbating alone without a medium, what do you suppose he would think about? You? Sure, some of the time. The girl down the street? Yeah, some of the time. An actress? Maybe. He's masturbating because it's fast, easy and requires zero commitment on his part. It' 100% guy.
Point is, this is not a problem unless it is cutting into your sex life.