X-ray vision doesn't prevent you from doing anything. If x-ray vision would prevent Superman from driving a car, because he couldn't see traffic signs it would qualify as a disability.
Actually it may be a better analogue than it first appears, and not understanding that might also help understand the situation as a whole.
Those without Xray vision shouldn't be expected to understand the downsides: imagine if you can always see what's inside a gift, or who is hiding behind a door?
Whilst it seems only positive, you lose out on something that's a fundamental part of ocular-typical upbringing.
Indeed babies learn, eg through "peekaboo" (a game in which an adult hides their face from a baby), about object permanence in part by not being able to see things and then to have them revealed. Peekabo also is the beginnings of parental detachment, learning to cope when you can't see your mother (or current favourite carer).
That sort of developmental difference could have untold social effects.
There are huge temptations to cope with, not just sexually. "I left the book in my locker" - well with Xray vision I don't have to accept the lie but can verify it for myself. "My sister's not home, sorry", well of course Supe-y can see she is, and [I think, with the Xray vision he has] see who she's texting "Superman can be a real jerk" to.
TL;DR -- One thing Superman may not see is the damage he's doing by not respecting personal boundaries, and by not playing along with people's white lies ...
