Someone who likes men, or is a homosexual. The term was engendered at a communal meeting in Boston encompassing a plethora of Boston's more affluent population. There a kid named Kevin ran into the meeting room and began jamming a banana up his anus and another one into his mouth. Than a large black convict who escaped from prison came in and thrust his large genitalia into kevin's or BOSTONMASSACREx's anus alongside the banana. He than said his name was Kevin and that his XBL gamertag was BOSTONMASSACREx. The whole of the non gay group was very offended and from then on referred to BOSTONMASSACRE as a homosexual fag.
Kevin bends over and a large black man puts hius genitalia into his anus. At which point Todd says wow way to be a BOSTONMASSACRE, f'ing homo.
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.