Villain is 45/20 but I don't have any great reads on him. I checked the flop because people who limp in PF like that usually take a stab at it.

Party Poker No-Limit Hold'em, $ Hero (4 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

SB ($314.42)
Hero ($203)
UTG ($148.50)
Button ($204)

Preflop: Hero is BB with 4, 6. SB posts a blind of $1.
UTG calls $2, 2 folds, Hero checks.

Flop: ($5) K, 4, 6 (2 players)
Hero checks, UTG bets $2, Hero raises to $8, UTG calls $6.

Turn: ($21) 5 (2 players)
Hero bets $15, UTG raises to $50.5, Hero ???