My girlfriend and I have been playing truth or dare from very early in our relationship. We know more about each other's past than even our closest friends. We know exactly what we've got up to, what makes each other tick and how far they are prepared to go. The riskiness and 'level' of the dares have increased over time. Each time pushing each other that little bit further.
My girlfriend loves getting naked and having sex outside, with the obvious risk of being caught. She'd mentioned previously that she wouldn't have a problem stripping in front of our friends if she was ever dared to. I thought it was only right then that I dared her to bare all on the Internet for everyone to see her incredibly fit body. She duly obliged.