I would think not as a matter of course. Accedentaly, perhaps.
is it OK for a mom to see her teenage son naked?
No, I don't think that's okay.
Only in a medical or life saving emergency......otherwise there is no reason a mother NEEDS to see her teenage son naked.
No, mom's should try not to see their sons naked too often. Not only is it embarrassing for both parties, but if it happens too often it could be considered "unhealthy".
It's also important for children to feel like they have a sense of privacy and know where the boundaries are between people.
Otherwise they will fail to respect these boundaries in real life, and end up with social problems or worse...
So moms out there, please try your best not to walk in on your son naked. Knock on doors before entering a room, don't go barging in... I know you gave birth to him so it's not anything you haven't seen before, but after a certain age it is no longer appropriate