Honestly, I don't think it would really matter if it was
silly on her part. The point is, she is grossed out/feels disrespected, and when she expresses that to her husband, his response is "Yeah, well my mom wasn't."
Now obviously, OP, you weren't there and you're getting this second-hand from your friend, but it seems like the best thing for her to say would be "I understand that. However, I am not your mother, and it does
bother me. A lot. Please respect my wishes."
Because we engage in slight behavior modification for the sake of our partners all the time. Not because one partner is more correct (although I think Marissa is, in this case
), but because we care about each other and don't want to needlessly annoy one another when a simple change would eliminate the problem. I have learned to take my shoes off in the house. DH has learned to comply with my weird organizational preferences. Marissa's DH can learn to put his cores in the trash/compost.