i spotted a guy once - no thank you, no acknowledgement at all after the first set so I went back to what I was doing. 5 minutes later I hear this goon whistle and I look up, he's looking at me and goes "Yep", beckons me over and lies down on the bench again.
I kept going with what I was doing and left him there, he sits up looking annoyed and calls out "Now!"
I left him to it but I've seen him since grabbing someone and making them hover around him while he works out.
I've thought I should have gone back and then left him mid set...