Isaiah Thomas took in last night's Red Sox-Mariners game, but which team did he root for?

All-Star point guard Isaiah Thomas has become a star in Boston, where he led the Celtics to last year's Eastern Conference Finals while averaging nearly 29 points per game. He's also a native of Washington state, having grown up in Tacoma, and played his college basketball at the University of Washington.
So it makes perfect sense that he would show up at Safeco Field for the Mariners' 6-5 win over the Red Sox on Tuesday night:

But one question still remains: Just which team was Thomas rooting for? His hometown Mariners, or his adopted Red Sox? He's thrown out the first pitch at Safeco before, but he's also been known to pop up at Fenway Park from time to time. 
The Red Sox certainly thought he was pulling for the away team:

The King in the Fourth! ?? ?? @Isaiah_Thomas pic.twitter.com/IwjgswqKUk

— Red Sox (@RedSox) July 26, 2017

The Mariners, however, had other ideas:

The world may never know.