Speaking as someone who has been in your husband's shoes, unless he's into hotwifing or something similar, he's definitely not going to be as happy about this as you are. You know how good you're feeling? Multiply it by a hundred and make it a negative, that's how it feels from the other side. The are better ways of saving your marriage than betrayal.
I don't plan for him to find out, and I'm not going to tell him just because I feel guilty. There's no guilt yet actually. I'm not having emotional relationships, just casual sex. Every time that the husband or wife gets told that they were cheated on it's not for their benefit. It's just that the cheater wanted to feel better. I won't be doing that.
No, I was told by someone else as confirmation after I had figured it out. He will find out one way or another. And it will break him. He will probably be able to get himself back together again, but there's a strong possibility you won't be there to see that. I'm happy for you that you don't feel guilty, that must make it a lot easier for you to look him in the eye. But the fact it's just casual sex and not an emotional relationship will make absolutely no difference to him. You aren't just destroying your marriage, you're destroying his social circle too. He won't know who knew, who helped cover it up, and worse, who he can trust. He may never recover. I have one friend from before my ex-wife's infidelity. One. Sure I see most of the others every so often. I can smile and joke with them. But I no longer see them as friends and do not trust them. Just because you get a kick out of something and think you can cover it up; it doesn't mean it's okay to do it.
I posted this in reply to your other comment, but I thought I'd ask it again here: Have you talked to your husband about the mismatch in your libidos? If so, how did that conversation go? Mismatched libidos are not uncommon, nor are they easy to solve, but they can be worked through if both parties are willing to do so. It sounds like a relationship or sexual therapist might be very useful for you both, if you're able to get one. EDIT: You might find this Reddit comment worth reading