[NL50]JJ on Thigh board. wud u fold here?

[flyerr]

My question is simple. What can he have here? my flop raise was very weak but I had a bad feeling about this hand. Would you fold in this spot?

Full Tilt Poker - No Limit Hold'em Cash Game - $0.25/$0.50 Blinds - 5 Players - (LegoPoker HH Converter)

SB: $81.80
BB: $50.00
Hero (UTG): $50.00
CO: $50.50
BTN: $51.85

Reads: <font color="blue">Villain had previously made a semi-bluff with bottom pair on another player for half his stack wich didnt work out. I had won 3 pots without showdown vs him. 37/23/4.8(115)</font>

Preflop: Hero is dealt (5 Players)
<font color="red">Hero raises to $1.75</font>, CO folds, BTN calls $1.75, 2 folds

Flop: ($4.25) (2 Players)
<font color="red">Hero bets $4.00</font>, <font color="red">BTN raises to $10.00</font>, <font color="red">Hero raises to $16.00</font>, <font color="red">BTN raises to $22.00</font>, Hero calls $6.00

Turn: ($48.25) (2 Players)
Hero checks, <font color="red">BTN bets $20.00</font>, Hero folds
Uncalled bet of $20.00 returned to BTN

Pot Size: $48.25 ($2.40 Rake)