I was at a fast food joint using the restroom and this woman brought her grown ass son into the womens room to use the bathroom like wtf.

It's possible that he's developmentally disabled and can't use the restroom by himself. It might have been more appropriate for her to have gone with him into the men's room. If it was a father with his grown daughter, I'm not sure what the best way to handle that would be. I guess if it was me, I would take my daughter with me into the men's room and have her use a toilet.

But that's my guess, she couldn't let him use the bathroom on his own. Now, if the guy was totally normal, that's different.