I think I'd call with the ace-high flush here, but not the king-high.

Boat's possible...but the jack-x combinations are all pretty weak.

Of course, the odds of him holding 2 spades isn't all that great either, but I've seen it happen.

Personally, if I have trips, and a 3rd suit comes down, I'm not gonna be betting huge into the hand. More than likely he has a flush or boat of some type.