10/20 flopped boat, turned worse boat - river decision

[Swatched]

Hand is vs an unknown player we have been playing HU for 60ish hands. We haven't seen many flops and he has yet to 3-bet me preflop. Before this hand I got lucky a few times and made a bluff or two and worked my stack to around 5k.
Hand in Question:

***** Hand History for Game 6514994066 *****
$2,000 USD NL Texas Hold'em - Monday, November 19, 00:57:14 ET 2007
Table Table 127832 (No DP) (Real Money)
Seat 6 is the button
Total number of players : 2
Seat 6: dunkey_punch ( $2 426 USD )
Seat 1: swatched ( $5 013 USD )
swatched posts small blind [ $10 USD ].
dunkey_punch posts big blind [ $20 USD ].

Holecards:
Dealt to swatched [ 7c , 7d ]
RAISE swatched , $60 USD
CALL dunkey_punch, $50 USD

Flop:
[ 7h , 9s, 9d ]
BET swatched , $100 USD
RAISE dunkey_punch, $315 USD
RAISE swatched , $675 USD
CALL dunkey_punch, $460 USD

Turn:
[ 9c ]
swatched checks
dunkey_punch checks

River:
[ 3s ]
swatched checks
ALL-IN dunkey_punch [ $1 581 USD ]
swatched ???

Thoughts on all streets appreciated.

[AlexKP]

Sick, I flip a coin...

Just hate this spot, I think I fold

[dickkemp]

he has a nine

[raptor517]

reraise flop bigger. no1 folds trips anyways.

[Swatched]

[ QUOTE ]
he has a nine

[/ QUOTE ]
what makes you say that?

[havewemetbefore]

A7 here for split