I wa checking to UTG (per Irisheyes' philosophy), but the BB lead out. Did he catch some crap 2 pair hand or something??

PokerStars No-Limit Hold'em, $0.05 BB (7 handed) FTR converter on zerodivide.cx

MP2 ($5.95)
CO ($6.93)
Button ($18.19)
Hero ($8.69)
BB ($8.48)
UTG ($9.30)
MP1 ($7.88)

Preflop: Hero is SB with 3, 3.
UTG raises to $0.1, 3 folds, Button calls $0.10, Hero calls $0.08, BB calls $0.05.

Flop: ($0.40) 5, 3, 7 (4 players)
Hero checks, BB bets $0.15, UTG calls $0.15, Button calls $0.15, Hero calls $0.15.

Turn: ($1) 9 (4 players)
Hero bets $0.5, BB raises to $1.25, UTG folds, Button folds, Hero ??