purple herbie
when you were a kid - twisting the nipple of (usually) a male so that the nipple area bruises and turns purple. NO - it's not a dick - it's a nipple, btw.
Timmy's purple herbie was visible the next day when I took my shirt off and saw purple around my left nipple.
purple herbie
to squeeze the cock till the head turns purple
joan grabbed john so hard she gave him a purple herbie