if he's not 4betting AA pre its likely that villain is gonna see a 4bet in this situation as KK+ since his 4bet stat will be really low and his 3bet is likely lowish as well, so not sure how he's going to suddenly portray that as being a resteal hand by 4betting pre.Hero has to bet something on turn so that he can maximise his bet on the river while still getting called by Kx.As played i'd just shove over the river bet ands hope he'd got KK