AA 4 handed against Blind raise

[orange]

.10/.25 NL 4 handed live. Stacks are all average, ranging $15-$30. Game is composed of one rock, a calling station/LAG type player, a TAG(myself),and a maniac.

Villan is the maniac, who raises blind every round when he's first to act. He is a good player who can play well postflop, and usually is a TAG in a 9 handed game. He respects me and I usually respect him. I have ~$30 and cover villan by a little.

Villan raises to $2 blind UTG (standard raise).
Hero is dealt AA in LP and raises to $7
all fold to villan, who calls.

($14) Flop: 3 K K (suites unimportant)
Villan checks
Hero checks

($14) Turn: 4
Villan bets $5
Hero calls $5

($24) River: 2
Villan bets $9
Hero folds

I figure it is a WA/WB situation. Considering that villan respects me, I feel he isn't betting without a K. Thoughts?