Honestly, it actually is a big deal, and I'd like to know what country they're in, because it doesn't matter that they are the roommate's parents, the roommate is an adult. The roommate should be learning how to do stuff herself and the parent could get the law called on them. That roommate mother has no right to judge anyone of what they wear. If her own mother has no problem with it, then I don't see what the problem is.