You really gotta watch out for this kind of thing. If it's happening with some frequency with the same three players, it could be a form of collusion. You raise, someone in the team might be strong enough to take you on but those to act later in the hand signal their weakness to their partner by folding out of turn. If he's strong enough, he's their last stand, but this time he's not, so you win.
Another form of collusion is two or three players betting up the pot, with you in the middle, making it very hard for you to see a showdown. Whiplash.
This might sound like paranoia, but it does happen, and you have to be wary especially if you're a new face in a local casino. In Michigan
, there was a band of locals doing this kind of play in the Manistee casino. Other players complained, the house did nothing. Now that cardroom is out of business. Some dealers and even some poker managers don't recognize that it's in their interest to police this kind of thing. In fact, they might even give a wink and a nod to the locals who come back every night to fleece the tourists - not through good play, mind you, but through this type of collusion.
In your case, it's probable that the two guys just made a mistake. But always watch out for suspicious patterns of play.
PS, I think you were playing $1/$2 No Limit, right? That's important info in describing the situation. It helps if you can give pot sizes and things likes that. Depending on how big your PF raise was and how big the pot was, your Post-flop raise might have been too big and killed the action. But you won the hand, so congrats. Win the session?