100NL: Straight on Flush FLOP

No-Limit Hold'em, $1.00 BB (5 handed) - Hold'em Manager Converter Tool from FlopTurnRiver.com

Button ($207.10)
Hero (SB) ($107)
BB ($170.25)
UTG ($101.35)
MP ($64.25)

Preflop: Hero is SB with 6http://www.flopturnriver.com/phpBB2/...miles/club.gif, 7http://www.flopturnriver.com/phpBB2/...iles/spade.gif
1 fold, MP calls $1, Button calls $1, Hero calls $0.50, BB checks

Flop: ($4) 5http://www.flopturnriver.com/phpBB2/...iles/heart.gif, 4http://www.flopturnriver.com/phpBB2/...iles/heart.gif, 3http://www.flopturnriver.com/phpBB2/...iles/heart.gif (4 players)
Hero bets $4, 2 folds, Button calls $4

Turn: ($12) 9http://www.flopturnriver.com/phpBB2/...es/diamond.gif (2 players)
Hero bets $10, Button calls $10

River: ($32) 10http://www.flopturnriver.com/phpBB2/...iles/heart.gif (2 players)
Hero checks, Button bets $16, Hero ???

The ony reads I had on villain was that he was playing a LAG game.
villain's 1/2 PSB bet on river can be either for value or as a bluff, however, with what hands would he call flop/turn on a flush board? Maybe 1 pair + heart, overpair with one heart, Ah or Kh? Maybe 2 pairs?
Standard fold?

i fold

i play same and fold the river

Obivious fold, but why are we sure he doesn't have the flush from the flop? This is one of the things that throws me off from time to time. He calls all the way, but I see people do this lots just to get opp to stay in the pot, knowing a raise will likely push them out. Is it the call on the turn? And what would you have done if no heart came on the river and you played it the same?

Sorry if I ask something obvious, but I'm trying to figure these things out :D

easy fold, 4 tone board. button isn't check calling two streets and raising the river without something

ez fold on the river and i play the rest the same. my standard with 2pr/sets/straights on monotone flops is to pot the flop and turn as long as the 4th suited card doesn't come, and usually c/c most rivers.

i play it the same and fold riv