Hi,
I don't think it makes sense as a stand-alone sentence (you need to refer to the fact that Rachel wants to go back to her office sooner than she should only to see Tag "doing sit-ups", dont'you?), so I'm posting some context here for you.
Hope this may help somebody answer ...
Rachel: Oh, I gotta get back to work.
Phoebe: You don’t have to be back for a half-hour!
Rachel: Yeah but, my assistant Tag does sit-ups in the office during lunch. Ohh!
I could just spread him on a cracker.
Chandler: Rach, if you have a crush on this guy, why would you hire him? I mean
y’know you can’t date him right?
Rachel: Oh no, I know that. I know that. Although, we made a joke that we spend
so much time together he should call me his work wife.
(from:
here)