Best fold i accidentally made

[Sundevils21]

I'm playing 2tables of NL25 on party and 2 $10SNG's. I am fortunate enough to make it heads up at both SNG's. So I'm focusing on them while pretty much just folding at my NL tables when this hand came up.
Party NL25
Hero(BB)$50
UTG $80
SB $20
Preflop: Hero is the BB with K /images/graemlins/spade.gif4 /images/graemlins/club.gif
UTG calls,Sb calls, hero checks(Im not really paying too much attention to this table, all I know is I have a crappy hand)
Flop: A /images/graemlins/club.gif4 /images/graemlins/heart.gif4 /images/graemlins/diamond.gif
Sb checks, Hero(notpayingattention) checks, UTG bets $4, Sb calls, Hero folds(still hasn't recognized what I had)

Turn: K /images/graemlins/heart.gif
Sb checks, UTG bets 6, Sb raises to 12, UTG moves allin, Sb calls.
(I am flipping through the tables when it hits me that I had K4)
River:2 /images/graemlins/diamond.gif
Dang it I kept thinking, I just cost myself a ton of money by not paying attention.
UTG shows A /images/graemlins/spade.gif:4 /images/graemlins/spade.gif and wins the pot.

[sniperd]

Just awesome! Sometimes in my home game, somebody will fold on their BB instead of checking (almost always by mistake, but sometimes not!) It's funny when a hand like this comes up.