25£/50£ overpair facing river overbet

[Chaoslord]

3-handed. villian is bengt sonnert, he is loose and very agressive and probably views me as decent lag i have been 3-betting him a lot with various results. i have seen him overbetting the river once in this session, he had top pair good kicker and was doing it for value, i looked him up with top pair top kicker. he has 8700£ i cover.

button folds villian raises to 200 (std for him) i reraise to 700 with KhKd
flop: Qc4s7h he check-calls 1000£
turn: 8h he checks - i check (?)
river 9d he bets 4000£ - i?

i know this depends a lot on the flow of the game but some general thoughts? at this point i havent played much against him maybe 200 hands total and nothing crazy happened so far.

/e oh and if possible i want responses from ppl who either have played with bengt before or are at least high stakes shorthanded players themselfes, i dont need advice from some random 0.10/0.20 player thanks!