Preflop: Hero is CO with 6 , 6 .
4 folds, Hero calls $1, Button calls $1, SB completes, BB checks.

Flop: ($4) 7 , 6 , 7 (4 players)
SB checks, BB checks, Hero checks, Button checks.
Why are you slowplaying underboats on draw heavy boards? Milk'em before they miss and get stack in against trip sevens, don't let them pair their kicker for free.

Underboat is quite vulnerable hand, play it fast.

If you have JT on JJTr then you can mess with slowplay but in a case above - easy 3 barrels.