Overbet the flop and play cautiously if called. Like, $15 or $20. Ideally you want to take the pot right there. You have two pre-flop callers who could have anything and this flop could definitely have helped them. With what types of hands do people call early position raises with in position? Usually small pairs and suited connecting cards (or a suited ace). Here, any pocket pair of eights, sevens, or fives has outdrawn you as would 7-8 suited. A pair of sixes would now have an open-ended straight draw. With big pairs in EP you generally want to either get all the money in heads up pre-flop or, in your case here, you make a large bet on the flop, if you're called, you try to check it down from there because your opponent has probably outdrawn you. That's why position is everything. He probably knows you have a big pair, but you have no clue as to what he has. It can be tough to play the big pairs in EP in NL unless you get a great flop.