The odd occurence that when you are going out with someone you inherit their best friend as one of your own good friends. Often occurs more that a girl will become very close to her boyfriends best mate than the other way round.
"You and Johnny are such good friends How do you even know him?"
"Oh Hes Toms best mate so hes my Best friend-in-law"
Your bestfriend's husband/wife or girlfriend/boyfriend. So if your bestfriend is cheating then you have 2. Also if your bestfriend has a celebrity crush and says they are married that's also your bestfriend in law.
n. software that is no longer sold or supported by the original publisher / developer, often found as free downloads on the internet because it cannot be obtained elsewhere. Not legal, but often seen as morally acceptable because the company that made it is no longer selling the title, nor releasing it as freeware, therefore abandonware is "keeping the gamealive", so to speak.
Doom II is not abandonware because idstill sells it, while The Incredible Machine is not sold, therefore is abandonware.