I actually remember the early days of the “suck” usage when parents were shocked by their kids using it. My mom had a cow when she heard my friends and me saying it. I think I might have been 10 or 11 at the time.

I knew then it had a vaguely sexual context, though as made obvious by my little anecdote, I wasn’t exactly sure what. ;-)

I don’t know if most people today remember that the expression is sexual in origin, but I do, which is why I try not to use it anymore.

Not that I get mad if I hear other people doing it. As you say, language changes.