Jace and Will
As per usual with any kind of party, Will had managed to find a way to be at the center of it all. He was having a very good time - enjoying talking to everyone and moving from place to place, flirting with everyone who would randomly let him. At the same time he made sure that Tessa had tea when she wanted it and that Jem remembered to eat something (whether those were necessary or not, Will appreciated the opportunity to be helpful and needed).
The party was just getting good in Will's mind when he noticed Jace. He'd not yet interacted with the young man other than briefly. Perhaps it was time for them to have a more in depth conversation. So he made his way to Jace and offered a bright smile and a hand to shake, "Hey there. I'm Will, nice to see you here."