Trust your feelings, Luke/sanity check

[adanthar]

50+5 Party SNG. The blinds are 100/200 and it's 5 or 6 handed, it's not really important. Big stack loose but not horrible villain with 3K limps UTG, everyone folds to me with 2K and I check a ten and a five in a BB even though you need them both to make a straight with.

The flop is KTx, two spades. I minbet 200 into the 500 pot because, hey, I can. He calls.

The turn is some low spade. I check. He checks behind.

The river is a T and I make a 200-ish value bet that maybe his king just calls. He raises to 700.

Can I fold?

...in retrospect, if I was going to bet I sure as hell should fold, but can I fold *without* that bet?