99 on Button

[Chaostracize]

First hand of $50-buy in, 20 person multi at Party. I limp in with 99 after 5 limpers. Flop is K88 rainbow. Checked to me and I check. Next card is a 4 completing rainbow, checked around to me and I check again. Last card K. Guess what? Checked around to me for the THIRD time.

Should I go for the value bet of 15 for a lone A, or should I just check it? Are my checks on earlier streets ok, or am I beeing too passive? Was my preflop limp too passive too after 5 limpers (including a UTG limp)?

Obvious result to follow. Thanks for any input on kind of a dumb post.

-Chaostracize

[Rakkad]

I would have made a stab at it on the flop, if I didn't, I would bet the turn, and check the river depending on how many people called the turn.