Sweet 4-8 Commerce game, 99 overpair on the turn

[Amaryllis]

It's a 9 handed $4-$8 game at the Commerce, loose passive as always:

<font color="blue">I raise UTG+3 with 99 after two limpers. CO and Btn cold call, BB calls as wells as the limpers.

Flop: 3 4 5r (6 players, 12.5 sb)

BB bets out. </font> It's his first hand, he is young and seems to have moved from a bigger game juging by his yellow chips.

<font color="blue"> UTG calls. </font> He is as loose as it gets, as passive as it gets, both pre and post flop. He would cling on 22 on a multiway AKT87 board and show it down.

<font color="blue"> One fold, and I raise. Folded to the BB who now three bets, UTG calls and I call.

The turn is a 4, no flush draw:

Turn: 3 4 5 4 (3 players, 11 bb)

BB now checks, UTG checks,</font> what would you do?

If there's interest, I'll post the rest of the hand as well.