That’s one of my favorite gestures. It’s immediately recognizable.
@ekg One that hasn’t been mentioned is 鮪 although the vulgar form is usually written in katakana. The regular form just talks about the fish. The other one is definition 3 on Jisho. There’s also fifth definition that isn’t mentioned, but it’s probably because that one refers to a specific fetish, just like 豊満.
There was also this post in the discussion on 広がる.