ATM is an abbrieviation that has several common meanings:

1: At The Moment: Used when refering to one's current temporal circumstances.

2: Automated Teller Machine: A machine that dispenses physical currency and performs the role of a bank teller.

3: Ass To Mouth: A sexual act commonly featured in hardcore pornography where a penis, sex toy or other implement is removed from a person's anus and re-inserted into their mouth. Not to be confused with anulingus.

Micro marriging is when your partner manages your personal day-to-day tasks with you much like a Micro Manager at work.

At the moment.

ATM is the acrynom for "At The Moment." People usually use it during a chat conversation or email.

either at the moment, or those ATM machines in banks that you withdraw your money from.

arse to mouth (the reason he fell in love with me:))

At The Moment

Background unknown, but i guess irc freaks