JJ on flushy board, bet/fold river?

[ParvelX]

Villain is a very loose aggressive guy who's preflopraises you shouldn't take too seriously. Seen hom cap with Q7s before and rasing with K2s.

$2/$4 Texas Hold'em (Split Limit) - 02:57:00 05/03/2007 ET
Table 'Sailboats (6 Max)', 6 seats max, Real money
Seat 2 is the button. Small Blind $1, Big Blind $2
Note: seat IDs range from 1 to 6
Seat 1 (playing) : Player 1, amount $34.95, amount bet $0, penalty (None)
Seat 2 (playing) : Player 2, amount $127.77, amount bet $0, penalty (None)
Seat 4 (playing) : ParvelX, amount $127, amount bet $0, penalty (None)
Seat 5 (playing) : Player 5, amount $71.25, amount bet $0, penalty (None)
Seat 6 (playing) : Player 6, amount $54.40, amount bet $0, penalty (None)
ParvelX: Small Blind ($1)
Player 5: Big Blind ($2)

** Dealing Down Cards **
Dealt to ParvelX: [J [img]/images/graemlins/diamond.gif[/img], J [img]/images/graemlins/heart.gif[/img]]

Player 6: Fold
Player 1: Raise ($4)
Player 2: Fold
ParvelX: Raise ($5)
Player 5: Fold
Player 1: Call ($2)

** Dealing Flop **
Community cards: [2 [img]/images/graemlins/spade.gif[/img], K [img]/images/graemlins/spade.gif[/img], 4 [img]/images/graemlins/spade.gif[/img]]

ParvelX: Bet ($2)
Player 1: Call ($2)

** Dealing Turn **
Community cards: [J [img]/images/graemlins/spade.gif[/img]]

ParvelX: Bet ($4)
Player 1: Call ($4)

** Dealing River **
Community cards: [8 [img]/images/graemlins/heart.gif[/img]]

ParvelX: Check ($0)
Player 1: Bet ($4)
ParvelX: Call ($4)
** End Round **

The bet on the flop is mandatory, the turn I think yes (does anyone check here and just call the river UI?) As played I'm thinking of a b/f line on the river. Costs me just as much as calling and probably folds some small spades.