Game LIVE full ring $1/$2  very soft game

MP call $2

HJ raise $8

CO (Hero) $400 call $8 with 99 Logic to not raise was...do I really want to play a huge pot with nines that could potentially be 4-5 way anyway?  Once people limp they don't fold at this table. A raise would have to be $25+ and then I would have to play a $100 pot that I really don't like when I see any over cards, so I opted for the lower variance line.

BTN ($150) Calls $8

SB Calls $8

BB Calls $8

MP calls $5

Flop K4d2 rainbow Pot $48

Checked to BTN who bets $12 and everyone calls but MP, I call thinking the odds are insane if I hit my nine i'm good and will likely get paid. But I know I am not likely to be ahead at this point.

Turn Jd which brings a backdoor flush possibility Pot $108

Checked to BTN again and he bets 25 and gives away that he has a vulnerable hand by his gestures and body language.  At this point I put him on a weak TP and realise in a 7 way pot it will be hard to continue if I rep strength on the turn and river.

Folds fold to me in the CO...so we are heads up...I raise to $75.  Thinking man this is a huge orphaned pot against a weak tight opponent with a likely weak holding... he will likely fold Kx in a multi-way pot just to this bet, and if not I can still shove almost any river card except a K. 

He snap calls in a weird way, which I didn't really know what to think...but it didn't seem super strong, more like a snap call to guard against a bet on the river.

River 6d bringing the backdoor flush...I shove for the remaining $90 of his stack, thinking this is a perfect card to bluff.  I would have played a diamond draw the same way....Snap call. He has Kd5d! Turns out I made the perfect read and play...but it he got his card on the river.  Which I felt great about.  He did agree he would have folded any non diamond, k, or 5.  So I liked the play...but not the result.

After thoughts:  I really liked the way I played the hand post flop.  I really liked my bluff line and I think I would have won the hand on any non diamond, K, or 5...so I just kind of got unlucky that he sucked out on my bluff spot:) I don't love the call pre with 99, but I had reasoning for just calling.  Looking back a small raise to $20 to discourage the BTN and blinds from calling would have made sense, but if the BTN calls the $20 it would have been the same multiway fest. So not sure if the hand would have played differently.  Some will call anything under $20 and nothing over $25.  So bet sizing is tricky to bet a few folds and not scare everyone away.  Also once they realize I raise a wider range than most they will call my opens/3-bets more than limps (it doesn't make sense, I know, but maybe its a fight or flight response?)...so I have to tone down my raises pre to not bleed chips in multiway pots I can't win very frequently.

Any thoughts?