Recent studies indicate that the excitement and passion of a new relationship subsides after two years. So...
....just a test. Arrange a babysitter, then, call your wife and tell her to meet you without any underpants on and wearing a skirt at such and such restaurant bar tell her to sit at the bar, not a table. I'll let you imagine what you are going to do after you see her sit down....maybe, you're already chatting with a woman there....
(caveat...don't have sex in public, but don't have sex at home)
Good Luck!