microwave-meal mate
Microwave-meal mates are people who you become 'close friends' with over a very short period of time by asking too many personal things in the early stages of the friendship and thus, creating the illusion of being close, when in reality,

it is a very forced and superficial way to get to know someone (e.g. playing 21 questions or truth). While this is a quick and easy way to become 'close' with people, the quality of the friendship isn't good and it doesn't last long, kind of like a microwave-meal. Slow-cooked meals are always better, just like friendships which take their natural course to becoming close and age like fine wine.
Jealous best friend: wow, you and the chick from the party last month have gotten pretty close.

Best friend: nah, she's just a microwave-meal mate. I'll probably forget she exists in a couple of months.