QTs in SB - bizarre playing by button

[Fiddler]

This is another loose (around 50% VP$IP) and kind of passive button, especially pre-flop. No read on BB.

1/2 6-max (5-handed)

Folded to button who calls, I complete in SB with Q /images/graemlins/club.gif T /images/graemlins/club.gif and BB checks.

Flop: 7 /images/graemlins/diamond.gif 5 /images/graemlins/spade.gif Q /images/graemlins/spade.gif

I bet, BB calls, button calls.

Turn: 5 /images/graemlins/heart.gif

I bet, BB calls, button raises, I call, BB folds.

River: K /images/graemlins/diamond.gif

I check, button checks!? What the!?

Ok, I'm clueless. Any advice is appriciated.

[imitation]

I think the hand is standard. I think you were either chopping, or QJ or maybe, though I think least likely, Q9. Unless you think Button has you pegged as agr post flop and is similarly agr and might try this with 7x.

[naphand]

I think Button has a 7 or 2 x /images/graemlins/spade.gif. He doesn't really like his hand too much, and tried to pinch it by representing the 5's. When that fails/he misses he checks behind. You will see this quite often from some players, although more usually after you have raised PF and they figure you for overcards.

Make sure you note this, as you will probably always need to call him down in spots like this.