Overpair on turn c/r by medium stack

[CobraGoat]

Villan was 25/14/2 over 50ish hands.



Full Tilt Poker, $0.25/$0.50 NL Hold'em Cash Game, 6 Players
LegoPoker Hand History Converter

Hero (BB): $50.70
UTG: $41.20
MP: $136.50
CO: $23.10
BTN: $47.55
SB: $29.25

Pre-Flop: T T dealt to Hero (BB)
2 folds, CO calls $0.50, BTN folds, SB raises to $2, Hero calls $1.50, CO calls $1.50

Flop: ($6) 3 8 8 (3 Players)
SB bets $4, Hero calls $4, CO folds

Turn: ($14) 7 (2 Players)
SB checks, Hero bets $7, SB raises to $23.25 and is All-In, Hero?

What am I beating here that plays this hand this way? Should I have just checked the turn? I was thinking a half pot bet to protect against overs hitting on river but if thats what Im worried about, they are only 12% to hit. So this is probably a turn check otherwise im turning my hand into a bit of a bluff?