[BluffTHIS!]

You other posters are just spoiled. These hand histories are not hard to read if you ever review your own.

Whenever you have raised preflop with AAxx and a flop comes with two high straight cards in a multiway pot, someone will often be slowplaying a set and more often someone will have two pair, so unless your sidecards hit with some kind of draw it is often better to check and not escalate the pot. In hand #1 you were presumably relying on holding the naked ace to be able to make a play if the flush came, though on the $25 tables it is wishful thinking to believe someone will fold a ten high flush. In hand #2 though you actually got a very good flop with one high card and two rags and no straight draws unless the opponent had something like 6543. So unless your opponent in this headsup pot is known for slowplaying sets, I would have either bet the pot again to prevent his making two pair assuming he would call with one pair on the flop (something like AJT9), or I would have check/called. Even if he had J8 and thus made two pair, you have a gutshot to admittedly the bad end of a straight, and if the board pairs low that often will win the pot. Again this all depends on whether you have a read on how this opponent plays various types of hands.