Scratching that itch after a work day is actually something of a recreational activity for me... feels totally like some kind of animal thing, not sexual, just... a good scratch. throw my head back, groan that groan you groan when someone scratches a really bad itchy spot between your shoulders that you can't reach... almost do the "dog wiggling its leg when you scratch its belly" thing.
Make sure you don't have a fungal infection (tinea cruis-- basically athlete's foot on your crotch) or anything worse, then just enjoy it. Or use something to control sweating down there if it bothers you that much.