Mirage 6/12 AA Hand

[Soviet Exile]

How's my line on this one?

First 6/12 table of the day. Half locals, half tourists. Average age 55, even with me (35) and some late twenties/early thirties guy on my left.

Folded to me in late middle position (actually the hijack seat if I recall). I raise with AA. Suits not important.
Late twenties/early thirties guy calls from CO. BB (older guy in stylish golf wear, who seems to be playing more hands than most) calls.

Flop: K,K,x. BB checks, I bet, and CO raises $5 all in. BB calls $11, and I call reluctantly.

Turn: Blank. BB checks, I check.

River: Blank. BB checks, I check.