While everyone else heads straight to the pool, picnic table, or cooler, this hero is quietly assisting the host even though nobody expects a guest to do so. Look for the person gracefully bowing out of a great conversation to open the screen door unasked. Without these people, society would probably crumble.
The weird new significant other
She brought HIM? What do those two have in common? He mumbled something about his band, and now he’s swimming with his shirt on. Finally, something to gossip about later!
The person who overdressed
You know the one -- definitely not in pool party attire, but also the most likely candidate to get thrown in at the end of the night (probably by The Big Kid) to complaints of a ruined brand new shirt and running makeup.