Utility definitions

Lorenzo is arguing with his girlfriend, Neha. They have been going out for a little more than two years.

NEHA: I$\text{'}$m leaving you, Lorenzo. Get over it$.$

LORENZO: Are you saying that being single will make you happier than you've been with me$?$ Speaking personally, I think the utility we've had in this relationship was much more than you could have had if you'd been single this whole time!

NEHA: I have taken an economics class and the word "utility" rings a bell. It's not that at all. We've had a fine time. It's that the $$ utility I would get by continuing our relationship isn't worth it anymore.

LORENZO: I've never been dumped by someone citing the law of $$ that? $-$ before. You're a piece of work, you know

Neha doesn't hear. She has already walked off, leaving Lorenzo feeling like something of a sunk cost.