Suppose the flop has been shown. Now the active person to the left of the big blind will check or bet the flop. He bets and then it's my turn and I choose to raise him and then he calls. Now after the turn card has been shown, who will do an action (check/bet/fold), the one to the left of the big blind(as earlier) or me who raised before this?
Suppose if I had only called his bet, then after the turn card has shown, who will act first?