UTG+1 is just terrible
SB is 37/9, straight forward and donkish. I've been robbing him blind.

Anyway can I fold this river?

PokerStars No-Limit Hold'em, $1.00 BB (8 handed) FTR converter on zerodivide.cx

MP2 ($19.35)
CO ($221.95)
Button ($161.05)
SB ($66.95)
BB ($24)
UTG ($23)
UTG+1 ($60.65)
Fnord ($167.70)

Preflop: Fnord is MP1 with 5, 4.
1 fold, UTG+1 calls $1, Fnord calls $1, 2 folds, Button calls $1, SB raises to $2, 1 fold, UTG+1 calls $1, Fnord calls $1, Button calls $1.

Flop: ($9) 4, 6, 7 (4 players)
SB checks, UTG+1 bets $3, Fnord calls $3, Button calls $3, SB calls $3.

Turn: ($21) 4 (4 players)
SB checks, UTG+1 bets $3, Fnord raises to $20, Button folds, SB calls $20, UTG+1 calls $17.

River: ($81) 5 (3 players)
SB bets $41.95 (All-In), UTG+1 folds, Fnord ???