Utterly confused with KK

[Emmitt2222]

This is one of the most confusing hands I have played in awhile because the bets kept coming from different places, what the heck is happening? Please tell me all the ways in which I butchered this. BB, UTG and MP1 are all pretty loose with UTG and MP1 being particularly so. BB is the most agressive around 3.5, UTG is around 2 and MP1 is just a fish

Party Poker 2/4 Hold'em (10 handed) converter

Preflop: Hero is CO with K[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/club.gif[/img].
UTG calls, <font color="#666666">2 folds</font>, MP1 calls, MP2 calls, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, Button calls, <font color="#666666">1 fold</font>, BB calls, UTG calls, MP1 calls, MP2 calls.

Flop: (12.50 SB) T[img]/images/graemlins/club.gif[/img], 4[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(6 players)</font>
BB checks, <font color="#CC3333">UTG bets</font>, MP1 calls, MP2 folds, <font color="#CC3333">Hero raises</font>, Button folds, BB calls, UTG calls, MP1 calls.

I felt this was similar to an example in SSHE where you have a pair of Q's and an ace falls. I was raising to protect my hand in a pretty large pot. UTG was pretty loose and agressive so I wasnt necesarrily going to give him credit for the ace.

Turn: (10.25 BB) A[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">BB bets</font>, UTG calls, MP1 calls, Hero calls.

While this card appeared scary at first, it actually is probably better because it slightly lessens the chance that someone has an ace. BB is even more agressive postflop than UTG and I don't think he would slowplay the ace on the flop, everyone else just calls so I call because its a pretty good pot and my hand could still be best. I thought he may have had a flushdraw or something but the other two called. Anyone find a raise or a fold?

River: (14.25 BB) 9[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, UTG checks, <font color="#CC3333">MP1 bets</font>, Hero calls, BB folds, UTG calls.

Final Pot: 17.25 BB

So a 9 falls and both of the first people check so I'm almost positive they dont have the ace, but MP1 is pretty passive and now he bets. I'm so confused but the pot is big and I think I should call down with the other two loose callers behind me. The only thing that MP1 could have is some random two pair maybe and he doesnt realize the aces counterfit him because there are no real draws. I almost raised but didn't, anyone see a raise or a fold here?

I really am just lost on this whole hand [img]/images/graemlins/confused.gif[/img]