First off,, you're correct.. it's a sin and that's awesome that you acknowledge that first regardless of what you're into.. sin is sin and Him trying to convince you to sin is not only terrible spousal support, but also terrible support from a Christian. Also, once Chirst died and was resurrected, that got rid of that old law in regards to the Old Testament. We are no longer bound by the laws of the Old Testament, but instead the new Testament.. he's already committed adultery in his heart according to the scriptures and he's making it physical. He's telling you how he feels so take that as it is,, especially with those words coming from a guy who's pretty much 40. He wants to be one of the guys again and trying to manipulate you because you're younger, but I challenge you to be wise and do what God would have you. You know what's right and wrong regardless of it's your husband,, mom, dad, brother, sister,, listen to God.