Depending on how many people are in the pot with you still, i would probably check both. If you make a small bet and someone hit their K in the first situation or A in the second, you're probably going to get raised because you'll be put on the draw that you're on, or one of the lower pairs...If you check and someone bets after you, call or fold according to your pot odds. If your first to act on a OESD or the nut flush draw, i don't think you can go wrong checking it to feel out the other players hands. Hopefully you'll see a raise that will indicate the top pair, and enough callers to give you a good price to stay in the hand with your draw. Worst comes to worst here, you see a big raise and have to fold. You lost a small pot. If you bet and are re raised, you might have to let it go and you lost more than you had to.