My wife and I make dares all the time.
One of my favorite was this. We wrote "LET ME BLOW YOU" on her chest in wide black marker. We also wrote "SLUT", and "COCKS WELCOME" on her pubic region and upper thighs. The dare was, we went out to one of our favorite bars (she wearing a low cut, sheer shirt and a skirt so short that her butt and pussy showed if she moved at all). Anyone who read the writing and asked about it (or what it said, or if they could try) got whatever the writing implied. (If the asked about "let me blow you," they got a blowjob, if they asked about "slut" or "cocks welcome" they got to fuck her). The best part of the dare is that she was not allowed to cover any writing that her clothes exposed, and she had to perform the act in the corner booth at the bar.
She blew 8 guys that night, and fucked 4. It was fantastic.