Showing Cards Before Hand is Over

I am in the habit of never showing cards at the end of a hand unless I am called or have not been shown a hand that beats mine in a hand that is checked down in turn. Last year, for the first and last time since, I got shown a card after being bet into before I had made my decision. After some discussion I was assured this was legal. I had flopped the K high diamond flush and bet the pot into two players, the last player to act shows me his Ace of diamonds and puts me all in - I called and the fourth diamond never came and I never thought of this again until last night.

I am in the bb with A [img]/images/graemlins/club.gif[/img] Q [img]/images/graemlins/heart.gif[/img] stack size is about 11 bb

sb is a calling station and erratic raiser who has been chasing second pair and flush draws to pot sized bets all night.

UTG is also a major calling station but much more passive.

Both have me covered by about 5 to 8 bb

UTG calls - sb raises 2.5 bb - I considered going all in here but figured I could get called by both I decided to call. - UTG calls - pot is now 7.5 bb

Flop is A [img]/images/graemlins/spade.gif[/img] 8 [img]/images/graemlins/heart.gif[/img] and a rag that made the flop rainbow and put no straight draws up.

UTG checks, sb bets 5 bb - I quickly go all in with my remaining 9.5 bb, and after UTG folds, sb has a decision of whether or not to call the remaining 4.5 bb into a 22bb pot.

When he hesitates I know he caught middle or bottom pair and based on his prior actions a call is definitely coming. If he calls and sucks out I am dead, If he calls and I win, my only gain is another 4.5 bb in a pot that is already 22 bb large. He would then be shortstacked at less than 10 bb.

He of course called after about 30 seconds and shows 8 [img]/images/graemlins/spade.gif[/img]9 [img]/images/graemlins/spade.gif[/img] and after rebuying four times during the rebuy period this guy finally gets lucky and hits a 9 on the river. I go home.

I'm thinking if I show the ace -
assuming this is legal - Ciaffone has an article on this http://www.cardplayer.com/poker_maga...amp;m_id=65539
- he folds. I of course did not show the ace as I did not even think of it until recalling the flush hand above later on but I am wondering if this type of play would be a decent maneuver in some very rare cases with certain conditions. Specifically, as above the pot odds are looking borderline or neglible, you know you are going to get called by someone prone to making marginal or even awful calls, and the gain you get from the call/win situation is not so great.