Man, that's a tough one, but I'd just fold it here and look for a better spot later. I agree that you are behind-cause you just have a pair of Jacks so far... So if you don't hit a diamond or a Jack you are dead. Meanwhile, at least one of your opponents probably has a set so far, and may hit the Full House to win even if you hit the flush. One of them may possibly be on a straight or flush draw, but judging by the betting, I think at least one, maybe both of them has a set. The flush might win, but odds are you won't hit it, and if you do it might lose anyway. It's tempting, but I'd muck it.

#1 in "Live Tells"-Generally he is concealing a smile????!!??? Are you kidding? Who the heck has to cover a smile because the're holding a strong hand? Anyway, you could still tell if a a player was smiling even if he covered his mouth. That supposed "tell"is just silly.

Gus Hansen's "Every Hand Revealed" is very good because it gives you an "inside view" of how a professional poker player thinks... Gus won the Aussie Millions tourney a few years ago and recorded every hand he played while winning it. Then he expressed his ideas about almost every hand in the book. It's quite interesting.