They definitely needed a vacation; he'd normally be more aware of someone's movements--even someone he trusted. So he's a half-second too late to realize what Thea has planned, even though he gets his arm up and crouches slightly to minimize the splash. "Hey! I didn't mean any offense."

But there is a grin. The water didn't bother him that much, and he got that she was playing. Two can play though, and he's tired enough to let himself indulge in some silliness. Especially after the not-quite-deep emotions of earlier.

"Besides, you know you're not winning this right?" Oh no, that is a smirk. BE warned Thea because that is a smirk.