Preflop: JTs we are playing for sure. the question is should we flat or 3bet? I think we should mostly flat and occasionally 3betting is fine. not wanting to 3b this all the time as he is in EP and should have his strongest range (even a loose player plays their strongest range from EP). the more likely the blinds are to squeeze the more we want to 3bet. with standard average players in blinds I'm probably 3betting 10-15% of the time and flatting the rest of the time. your size is good and standard.
FLOP: OK well we made a preflop play, it didn't work like we hoped and we got called in 2 places. we completely whiffed the flop. This is a good candidate to check back with the intention of giving up unless we improve on the turn. we have to have some giveups or we are over Cbetting. Our 3bet bluffs that can continue here are: any of the diamond hands as well as JTcc, A5cc, A4cc, and any of the T9s (already has a gutshot and 2 overs).
TURN: As played definitely checking the turn.
RIVER: It's a close spot....but not as close as it might seem at first blush. which hands do we think he A) opened in early position B) called a 3bet from out of position and C) called a cbet in a multiway pot? it's draws, sets or overpairs mostly. the diamonds missed but the most obvious open ender got there. and his overpairs should feel pretty safe. and his sets are boats.
he would need to be
bluffing with 2 big diamonds (KJd, KQd, AJd, AQd, AKd) or turning 88-99 into a bluff. most players wont turn 88-99 into a bluff here so we are basically down to the 5 or 6 combos of missed diamonds.
now lets look at his probable value: 77 (3) 66(1) TT(1) JJ (3) QQ (6) 89s (3)
he has about 14 combos of value if we DON'T include all the random 6x suited he apparently has in his range. Maybe sometimes he jams QQ pre, but he also has some random 6x suited so something like 14 combos of value is probably in the neighborhood.
14 value : 6 bluff
ratio: 2.33 :1 value to bluff
pot
odds we are being offered: half pot bet = 3:1
pot odds
so based on that alone it is a call.
HOWEVER, we do not close the action. we must consider this. also, in general villains are less likely to suddenly bluff the river when they are not the aggressor.....and this is even more true when betting into 2 people.
as such...I think he will have fewer bluffs than he should and I lean towards a fold. it is admittedly close but I'm folding here.
Cliffs notes: check back flop. as played it's an uncomfortable but disciplined fold on the river.