Pre-Flop I'm betting 150 in your spot against a loose player, I don't mind taking the pot IF he folds, and you've got a great hand to see some action with, plus if the board does come up J 9 3 (as it did) and he holds AJ you're likely to get paid off.
Post-Flop, with the two-diamonds out I definitely would raise - I think it's all about the odds
, and if you always make it go against the odds for your opponents to call, and they do -- you're mathematically 'supposed' to be a winner in the long run. Flat calling tells
him that you're holding a pair with a weak kick, or you're chasing -- you don't need to represent a chase, you've got a solid hand.
The turn looks tricky to me.. he's been playing loose as you've said and I could imagine him getting in there with 3-4 suited like the rest of the donks... especially if he's been betting every pot..
It would seem to me that 260 is about the size of the pot at that point.. I'd have to see how much this guy bets with which hands, I can't go off of not seeing him play... but that seems like a bet to get YOU off of a flush draw, so, again I'd be thinking a Jack, or 3-4.. I'm probably wrong in that guess - and I don't even know how to try to decide which one I think it is of the two...
I'm not trying to give advice here, I'm just giving my insight. My game sucks, I signed up to this board today because I'm looking to improve it.