You know keggate. You know marmongate. but do you know hatgate?
introducing my concept. Basically, as we can see in the images below, the original hat configuration (this can be confirmed with pretty much any other picture from the party) is as follows: Mack arrives wearing Will's hat. Celtics guy is wearing a cowboy hat. Microphone guy is wearing a snapback with a green band (or whatever that thing is called).
Throughout the day, at some point, snapback guy acquires Will's hat (I also think that it might have been his shoe that Mack ended up with?), and on two separate occasions Mack acquires the cowboy hat AND the snapback.
(swear I'm not a stalker or a creep, I js noticed the hats changing around while I was digging around for a fic and thought I would share).
^ photographic evidence