The picture you have painted is not what God has demonstrated. Your claim is that to acknowledge God's holy Ten commandment law as still binding on us is to commit adultery against Jesus. Adultery is to have a relationship with someone other than your husband, in this case Christ/God. The Ten commandments originated and was given by the same God/Jesus. So how can there be adultery? Can one commit adultery with one's own Husband now? obedience is a another word for adultery now?
Your appeal to Romans 7 does not help your cause, for a holy consideration of the text demonstrates the complete opposite to what you have portrayed.
4 Wherefore, my brethren, ye also are become dead to the law by the body of Christ; that ye should be married to another, even to him who is raised from the dead, that we should bring forth fruit unto God. (What does he mean here? the answer is given in the next verses)
5 For when we were in the flesh, the motions of sins, which were by the law, did work in our members to bring forth fruit unto death. (is it not clear here that we violated the law in our fleshly state committing sins which would cause eternal death, we do not need a theologian to decode that for us here!)
6 But now we are delivered from the law, that being dead wherein we were held; that we should serve in newness of spirit, and not in the oldness of the letter. (We are delivered from the law, how? By the removal of the law? No!! but by walking in newness of the Spirit!! We don't do what we use to do! That is confirmed below.)
7 What shall we say then? Is the law sin? God forbid. Nay, I had not known sin, but by the law: for I had not known lust, except the law had said, Thou shalt not covet.
So this text confirms that there is no adultery in keeping the law of God as you want to suggest.