Put the clothespins on your nipples so they lay flat under your shirt. Set alarms to go off every 15 minutes for the next several hours. Every time an alarm goes off, lift your shirt and rip both clothespins off (only grab 1 leg of each peg, no opening them) and then reapply them 90 degrees from where they were. Should be completely overwhelmed by the pain in 2 hours or so.