tough hand with monster

Hero ($85.00)
Button ($107.50)
SB ($103.00)
BB ($162.00)
UTG ($19.75)
UTG+1 ($99.00)
MP1 ($91.00)
MP2 ($87.75)
MP3 ($32.50)

Preflop: Hero is CO with K:club:, K:spade:. SB posts a blind of $0.50.
UTG raises to $2, UTG+1 calls $2, MP1 calls $2, MP2 folds, MP3 folds, Hero raises to $8, Button folds, SB (poster) folds, BB folds, UTG calls $6, UTG+1 calls $6, MP1 folds.

Flop: ($27.50) 4:spade:, 5:spade:, 7:spade: (3 players)
UTG checks, UTG+1 bets $2, Hero raises to $22, UTG folds, UTG+1 raises to $91, Hero calls $55.

Turn: ($195.50) A:diamond: (2 players)

River: ($195.50) 2:diamond: (2 players)

Final Pot: $195.50

UTG+1 was on a Ace high flush draw and missed, but the ace on the turn beats you anyways?

There's so much that can have you beat there (though, hopefully the PFR took away any possibility of a straight).. I think you might want to only call the flop or fold. Though you do have the 2nd nut flush draw.

I'm not sure of the best play here at all.