One of my early mistakes - I started dating the woman who would become mrs_godix in 1998. This was one year after South Park started and it was still the huge popular thing (and was still funny). So my future mother in law decided to get me a Chef stuffed doll. This one in fact:

Now I know there's no sense of scale in that picture, but let me tell ya, his hands are PERFECTLY spaced for grabbing tits. So one weekend around christmas they give me this. Immediately after opening it, I turn around and make this doll grab my wife's tits and basically molest her with it. On her parents couch. While her parents were watching. By time it dawned on me that this was a bad idea, I had already done it so I figured fuck it and kept doing it. It's not like if I stopped quickly that I'd be forgiven or something.
I got lucky though, both her parents found it hysterically funny. So unlike most married men, I can actually be myself around my parents in law without worrying about being on good behavior. There are limits though, another time I learned it is a very bad idea to ask how all the big tittie genes ended up with my sister-in-law instead of my wife.
As an added bonus, from then on I was not required to go to family things with the extended in-laws. In fact, I'm often encouraged not to. Especially if the very Christian branch of the family will be there.