Reads on Villain, if he had the A, he would've bet out. 99% sure he's on the draw.

Can't find the hh (stupid Martin's Poker), so it looks like this will be by hand. Sorry.

Martin's Poker £50 No Limit Hold'em (4 handed) FTR converter on zerodivide.cx

Preflop: Hero is Button with K, K.
1 fold, Hero raises to £2, 1 fold, BB calls.

Flop: (£4.25) A, 4, 5 (2 players)
BB checks, Hero bets £3.5, BB calls.

Turn: (£11.25) 3 (2 players)
BB checks, Hero bets £8 , BB calls.

River: (£27.25) 2 (2 players)
BB checks, Hero bets £77 (all in).