OP didn’t mix anything up, it’s a valid use of “rude” as a synonym for “crude”. Unlike “lewd”, those don’t necessarily imply something is inappropriate due to sexual content - you could use it if there were a lot of swearing or toilet humour, as well.

Lewd or games you don’t want your peers to know but want to play without creating a 2nd account.

I had a professor that was gifted Genital Jousting once.