more value?

ive been at the table for 2 hands, he hasn't folded pre yet.

PokerStars No-Limit Hold'em, $1.00 BB (8 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

Hero (Button) ($100)
SB ($112.20)
BB ($60)
UTG ($99.50)
UTG+1 ($195.70)
MP1 ($86.75)
MP2 ($100.50)
CO ($480.55)

Preflop: Hero is Button with 5http://www.flopturnriver.com/phpBB2/...es/diamond.gif, 5http://www.flopturnriver.com/phpBB2/...miles/club.gif
4 folds, CO calls $1, Hero bets $4, 2 folds, CO raises to $7, Hero calls $3

Flop: ($15.50) Qhttp://www.flopturnriver.com/phpBB2/...iles/heart.gif, Khttp://www.flopturnriver.com/phpBB2/...miles/club.gif, 10http://www.flopturnriver.com/phpBB2/...iles/spade.gif (2 players)
CO checks, Hero checks

Turn: ($15.50) 7http://www.flopturnriver.com/phpBB2/...miles/club.gif (2 players)
CO bets $1, Hero calls $1

River: ($17.50) 5http://www.flopturnriver.com/phpBB2/...iles/spade.gif (2 players)
CO bets $5, Hero raises to $15, CO raises to $25, Hero?

If you've only seen two hands from villain, you have no read. With no read, I probably just call here. It seems like villain is trying to string you along. AJ or other sets may show up, but truthfully, I think you're winning most of the time. But, I'd rather not push without a read.