How do I tell a player that the entire party has noticed that he has gotten flakey, and that his flakiness has almost exactly corresponded to his getting a girlfriend, and everyone is kinda sick of him dropping out last minute…? Even the members with spouses and kids are managing to keep things in order.

@NullNowhere Start by acknowledging that you get why. Dude is obviously high on the girlfriend supply at the moment.

Then set boundaries, since you are all scheduling this it’s a scarce resource. Emergencies happen, but this clearly isn’t it.

Then end with an out. Does he want to take a break? The problem isn’t the GF or spending time with her, the problem is the lack of clarity.

I think an ultimatum is kinda shitty, but requesting introspection isn’t. I.e. he should figure out what he values.

Imho. Good luck!