I have walked to a publich place with a vibrator (turned on) in my pants, worn women's underwear in public (under clothes) and been ordered to masturbate in a public toilet. Also walked in public with my cock and balls tied up and wearing clothes pegs.

Nothing so public as above, and always 'in secret'. About the most public thing I have done is go into a shop to buy lingerie and make up but that can be explained as 'buying for a girlfriend' if anyone asks.