The abbreviation for overtime which is code word for having sex. This can be usefull when the boys want to have a conversation in the office without violating HR policies and remain stealthy.
Eric: "Yooo bro how was your weekend!? Put in a lot of OT!?"
Jessica to Sarah: "Jeez Eric and Jimmy are always talking about OT, it's weird though I'm usually here on the weekends and I never see them in the office."