The facts: a man and woman were engaged in sexual intercourse, during which he, well, broke his penis. He sued, claiming that his partner was negligent because she failed to exercise "reasonable care" in the course of their activities.
The ruling: the Massachusetts Appeals Court concluded, in an opinion strikingly devoid of puns, innuendo, double-entendre, or any other literary devices (an impressive showing of judicial restraint), that persons engaged in consensual sex do not owe each other a duty of reasonable care, so you cannot sue your partner for sexual negligence. However, partners do owe each other a duty to refrain from "wanton or reckless conduct," meaning intentional conduct that carries with it a "high degree of likelihood that substantial harm will result to another." For example … well, I’ll leave the examples to you. We are trying to maintain our PG-13 rating, after all.