20/40 Getting aggressive

[MRBAA]

Here's my problem with this specific hand:

I'm fine with the raise on fourth -- you may have the best hand, you may not. I often play split aces by limping in a four way game, but I also would play hands like (JQ)A, three flush, (22)A. But when he calls on fourth and makes an open pair on fifth and bets...the gig's up. Small pots in short games, got to be able to do that old raise/fold thing. Cause if he does have aces up, or even sixes up, you in trouble.