Well asking sarcastically like that def is the way to go.
Just because you use they/them as pronouns doesn’t mean proper sentence structure is thrown out the window.
“Yeah, Max is pretty awesome! They’re super nice and neat. Yeah, they prefer to be called they/them, it’s what makes them comfortable! As a good friend I wanna respect their wishes!”
“They’re pretty funny, we took some photos! Here look! Wasn’t that fun Max? Why don’t you tell my friends you want to be called they/them, so you don’t get misgendered or feel uncomfortable? I’m sure they’ll be alright with it. If not then we don’t need to hang out with them ok? My friends can go suck it.”
“Max, you’re hilarious!” “Yeah Max was there, they didn’t enjoy the food.”
I mean really, you’re just replacing he/she stuff with they/them/their/theirs/they’re etc. Just like you would when talking about a group, it’s the same thing. Yes you can refer to them as just their name, but after a while it just sounds awful, so use their pronouns. And yeah, not all people who are Agender go by they/them either. So ask for their pronouns first! You want your friends, or others, to be comfortable around you, like any normal person would.
You would feel gross if people called you the wrong pronouns all the time wouldn’t you? Called you a gender you weren’t? Some people are ok with it, some people hurt when you do that. Just respect them alright?