$1200 eff. I'm in BB with K♥ K♠ V limps MP1 and there are 2 more limps after him and I open to $35. V makes it $125. I flat.

Flop: J♥ 8♥ 3♠ Pot $267 I check, check
Turn: 4♥ Pot $267 I check, V bets $175, I call.
River: 3♦ Pot $617 I check, V shoves $900

Some info on V. He limps fairly often so obviously I can't say he's overall solid. He does some things well enough. He does have a substantial aggro side to him so he's capable of stuff like 3bet bluffing, etc. and sometimes his aggro stuff is good and sometimes it's spewy.

Is he capable of a river overshove bluff specifically? I don't know. Big maybe. I know that I severely underrepped my hand and my line looks pretty weak but that doesn't necessarily mean we should call.

1. Should we just 4bet/GII pre instead of flatting?
2. What should we do as played?