Originally Posted by canadiancow

It's both.

If I want a drink and I need to use the lav, I'll walk up, check whether they're sitting and eating or whatever, and then say either "Could I get another rum and Coke Zero, no rush, I'm using the lav?"

If I don't need the lav, and they're sitting down, I'll ask "Could I get another rum and Coke Zero when you have a chance, no rush?" If they're standing up in the galley, I'll ask for it and let them decide whether to do it right then and hand it to me, or send me back to my seat to wait.

When they hear the call button, it could be "drunk cow wants another drink" or "someone is having a medical emergency", so if you want to go up to the galley for service, I'm pretty confident they'd prefer that option. Because for the call button, you might actually be jerking them out of a break because they think something important is happening.

But I've definitely had a lot of crew tell me to just hit the call button if I want something. And many others who thank me for not hitting it. I still haven't figured that one out, even as MM.