It really cones down to butt or crotch but I would have to go with crotch. When you scratch your butt to get rid of the itch at least it's clear what you did or they'll think you have a wedgie.
When you do it in the front aomething else could come to mind...
I would say butt, because its so uncomfortable and could make you walk a little weird. Sometimes I need my mate to walk close behind me so I could itch it lol.
I feel it's easy enough to pass off a dick scratch as adjusting your pants, but getting one of the butt itches right up there... you can't play that off. Maybe a cheek one, though.
When your standing in a waiting line and everybody is looking in front of them (towards my back) and they can see everything i do. Very annoying. All itchy places are annoying
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