This is standard, right? (I would've folded to a turn raise.)

UTG+1 is tight-passive.
MP2 and SB are loose-passive.

Party Poker 1/2 Hold'em (10 handed)

Preflop: Hero is BB with [Ks], [Kd].
1 fold, UTG+1 calls, MP2 calls, MP3 calls, SB calls.

Flop: (10 SB) [5h], [2h], [3s] (5 players)
SB checks, Hero bets, UTG+1 calls, MP2 calls, SB calls.

Turn: (11 BB) [Jh] (4 players)
SB checks, Hero bets, UTG+1 calls, MP2 calls, SB calls.

River: (15 BB) [8c] (4 players)
SB checks, Hero bets, UTG+1 calls, MP2 calls, SB calls.

Final Pot: 19 BB

you'd fold to a raise on the turn right?

Yeah, I would have folded to a raise on the turn. I may have folded to a river raise, depending on where it came from and if anybody else cold-called it.