Must slowplay sets!!??

I was in the a tight-passive daytime 10/20 limit he game at Foxwoods as in the worst hand nominee below. This was several hours before the J9 hand, the table was much calmer. Except myself who was tilty and frustrated.

Two tight players limp from MP. I look down at 77 and raise from the CO. bb and limpers call. (8 sbs).

Flop 7h 4d Ad. They check, I bet and only first limper calls. He is generally more aggeressive than the average daytime regular so I had hoped for a c/r.

Turn As. Check, I bet, He called.

River Ah. Board is now A A A 7 4. He checks. Suddenly I realized I might as well be holding 72 off-suit. If he was hanging tough with a hand like JJ, I am crushed.

So I tabled my pocket sevens. He chuckled and said "Wow, I thought I was going to trap you," flashed me his 44 and mucked them.

Discussion: I guess that is why they slowplay sets... Interestingly this man had been on a losing end of set-over-set (222 vs KKK I think) an hour earlier with another tight daytime regular (I should just call them dinosaurs). That hand had the players bet/raise/3bet/call the turn. The river went check/check as a dangerous flush card appeared :> All in all he had lost with a set or trips six times that afternoon and the game had only been going on for about 4 hours. He maintained his composure, and I wish that I could do so like that too.

he checks,