Great ask, just the kind of thing I like!
Get an old bra (or do without one if you can – lucky you) and cut out 3cm wide holes exposing your nipples through them.
Wear a thin t-shirt over the top (and add an open jacket if it’s cold).
Go somewhere like a shopping mall and secretly play with your nipples with your arms folded across your chest to hide it. Pinch, rub, pull, get them super hard (cold air will do too but it’s better to have them hard from arousal).
Then interact with people, and for every five that clearly look at your exposed nipples poking out through your t-shirt you can go and edge in the rest room.
A t-shirt like this would help your cause:
Earn five edges and you can ruin an orgasm.
Earn three ruins and you can cum.
Yes all in the public restroom. When you ruin you must be topless. When you cum you must be naked.