"Good" cards, bad situation

One off the button I'm dealt
:kc: :ks:

(first time I've seen a pocket pair above 99 in about 500 hands of hold'em, mind you)

One EP limper (solid player) ahead of me so I raise, hoping to isolate. Poor player on the button behind me calls. SB (mediocre player) calls. BB folds.

Flop comes
:9d: :6s: :4d:

SB checks. EP limper bets into me so I raise. (put him on something like A9 suited)

Button calls. SB calls. (one or the other has a flush draw, I'm sure) EP folds.

Turn card:
:8c:

SB checks. Even though they're getting the odds I can't let them get there for free. I bet again. Both call.

River is
:td:

SB bets out. I'm sure the button will raise here so my best move is to fold, which I do.

Results hidden:
Button does indeed raise. SB calls and turns over the king and jack of diamonds. I guess the button thought his straight would be good, or perhaps he had a smaller flush. He didn't show.