My father in law pees in front of me!

My father-in-law has always been weird and innapropriate around me ever since I met him. 
​Its gotten way worse though. Recently he started peeing in front of me! He and my mother-in-law came to me and my husband's house to have dinner. He went to the bathroom right off the kitchen and didn't close the door and just whipped it out like it was nothing and went at it! He did this TWICE while he was at our house! I was really shocked because no man has ever done that in front of me. My husband told him that's gross and he just mumbled something. 
After a while my husband and I went to their house for dinner and he did the same thing in front of me! It was worse at his house because I was in the living room and the bathroom is really close and I couldn't help but notice what he was doing. I just pretended I didn't see. 
​When I told my in laws how that grossed me out, they laughed and said I was overreacting. They said they weren't raised the way I was. Well that's a good thing! I would never do that!
​He used the excuse that when men use the restroom they all pee next to each other at the urinals. I said, "Well most likely the man standing at the urinal next to you isn't your daughter- in-law!" 
​They just act like I'm insane for being offended. Am I crazy for not wanting to see my father-in-law's penis while peeing?! Is this a normal thing for a man to do?!