[DoubleDeuce]

I agree with JimK, bet it and see if he wants to stick around after 5th ST.

I know at the lower stakes people will take a card off on 4th ST. Usually this would be more read dependent at higher stakes but you just sat down.

If he calls, you can probably check it down and/or fold to a reraise or a bet.

Plus hitting an ace and him hitting a six is big-time brick unless that somehow made 2-pair or trips for him. Most of the higher cards are dead, so unless he slowplayed split aces on 3rd (or big hidden pair), or hit a 1-out Ten on 4th then you are ahead and he's drawing thin.

Also you will must likely have position on 6th, you will have an opportunity to check behind and probably seal a cheap showdown. If you do draw the lead on 6th, it could really strengthen the look of your hand and/or take away another one of his high card outs. That could be another tough decision on whether to check or lead though...