[ike]

Don't have HH, sorry. Early in a session against an opponent I've never played before. We've gotten it in light and I've been losing. Seems very aggressive, he's made multiple shockingly thin value bets that I've paid off with worse. These have mostly been in small pots, crap like flop and turn get checked thru and then he vbs river with bottom pair and I call queen hi and lose on AKTT9 type boards. I haven't caught a big bluff from him but I'm quite confident he's capable, not necessarily in this spot specifically, but in general. (Ya, I game select good.)

25/50 effective stacks 7k

I make it 150 on the button with A3o, he calls.

Pot 300

Flop Ac 3c 2c

He bets 225, I call.

Pot 750

Turn Ac 3c 2c Ah

He bets 650, I call.

Pot 2050

River Ac 3c 2c Ah 4c

He checks, I bet 1700, he shoves ~6k

Obviously everyone's first reaction is going to be "You have a full house HU, one of the better possible ones even, CaLVlALa CAllAlAlALLALCLCLA ACclALlcLACLA CLALCALCLACL ACLAAL" but what am I expecting to beat?
Does he really take this line for value with worse often enough? Is he ever bluffing?
More specifically, A) how does he even get to this spot with a hand that wants to try to bluff? and B) what hands does he expect me to bet/fold this river with (or bet/call for that matter)?

Edit: Its definitely relevant to this hand that I'm pretty sure any two suited, and likely more combinations of 5cXy than you might expect, are in his range to call OOP preflop. He has shown up with 32s after calling a raise from the BB.