"cup of coffee" is code for date. Plausible deniability and all. There are other ways to talk that are less ambiguous.

As a straight male I've asked plenty of people, both male and female to grab a cup of coffee. So far no one seems to have been confused. They all understood it was just getting coffee and chatting.

Ok, then what's the code for cup of coffee?

The same. The only reason plausible deniability works is that it's ambiguous.

Ambiguous might not be quite the right term. In many cases for such an invite, it's desirable that it be pretty clear you mean a date, but you still retain deniability.

I guess you could say you want the implication to be clear and fairly unambiguous, but not explicit/provable.

Double entendre comes to mind.

"Hey, I'm heading out for coffee in 15, want to join?"

There is a big difference between "lets meet and talk to each other for an hour at the coffee shop on the weekend" and "We are at work, lets take a quick break!"

"Cup of coffee" -- it just depends on the context and how it is asked.

"Want to grab some (Starbucks|Blue Bottle|Peetz|etc)?" Maybe they'll just get a cookie.

it's also sad that you can't just call someone to netflix and chill....right?

No. I prefer to watch movies snd shows alone, so attention needs not to be divided.

"Netflix and chill" is current code for having sex. The idea is that you go over to someone's house turn on Netflix and proceed to ignore it while you have sex. @hnbroseph was playing off of the fact that this is another phrase that when taken literally is innocent, but has implied meaning in a certain cultural context.

Though "Netflix and chill" is probably less ambiguous in most cases since it wasn't a commonly used phrase before it gained its implied meaning.

I thought this was code for having so much bandwidth you can waste it

No, because it's a universal tongue-in-cheek way to state you want to have sex. "Cup of coffee" to "I want to fuck" however, is a stretch.

Once again, inviting someone over to your place for coffee after a night out isn't the same thing as inviting a coworker for a cup of coffee in the middle of the day.