the sexual act of having forceful, unprotected sex with a partner, ejaculating inside them, then killing them. This act is illegal in all 50 states and is highly frowned upon elsewhere. The act is obviously named after the event where 5 Bostonians were killed by the British in 1770.
Guy1: dude I have to get out of here quickly.
Guy2: Why man?
Guy1: I just gave this girl a boston massacre and the cops are after me.