I know this isn't really a big deal in the grand scheme of things, but I can't stand it when people use those words when talking about men and women, both in reference to themselves and about other people.
I had an ex who used to refer to himself as a lad constantly...he was 27 years old and he would call himself a lad FFS. I couldn't help but constantly think "no you're not a lad, you're a fucking man". He also referred to me as his "lass" even when I told him that I didn't like it. I am not a lass. I am a grown woman.
I've heard other people do it so I guess it's a thing but I hate it.
I also realise I'm probably biased as I dislike the words anyway, but it just seems even worse when it's used to describe adults.