When to pump and dump?

I’m an exclusively pumping mama I pump every 3 hours. Well I’ve been dying for some wine the last few days, but I’m not sure how the pump and dump method works and honestly it will kill me to have to dump lol. I’ve seen so many different things saying it doesn’t need to be done.

So what I’m asking is when do I know I need to pump and dump? How much can I have before I have to pump?