Constrict on enemy turn

[Koraxs]

Hi all.
Need a little help.

Situation: animal companion snake-constrictor with constrict (Ex) attack orc.
1 round:
Snake-constrictor step:
Snake try to attack (succes), give damage(bite+constrict) and try to grab (succes).
Both creatures have grappled condition now.

Orc step:
He attempt to break the grapple as a standard action by making a combat maneuver check.
Or
He can take any action that doesn’t require two hands to perform, such as cast a spell or make an attack or full attack with a light or one-handed weapon against any creature within your reach, including the creature that is grappling you.

Question:
Snake-constrictor deal constrict damage in case of such "orc activity while grapple"?
Or it's fake and snake-constrictor deal damage as normal just on his next step when maintain the hold/release poor orc from grapple??

[Diego Rossi]

Constrict activates only when you make a successful check to start or maintain a grapple. It isn't an attack of opportunity, it doesn't trigger because of other people actions and you can't make attacks of opportunity while grappled or grappling.

Trying to break free from a grapple is an action of the grappled creature, the grappler uses its CMD to defend, it doesn't make a grappling check.

AoN wrote:

Constrict (Ex)

Source Bestiary 6 pg. 291, Pathfinder RPG Bestiary pg. 298, Bestiary 2 pg. 295, Bestiary 3 pg. 293, Bestiary 4 pg. 291, Bestiary 5 pg. 291
A creature with this special attack can crush an opponent when it makes a successful grapple check, dealing bludgeoning damage in addition to any other effects caused by a successful check, including additional damage. The amount of damage is given in the creature’s entry and is typically equal to the amount of damage caused by the creature’s melee attack.

[LordKailas]

What Diego says is correct. This also means that the proper sequence for round 1 is

Snake tries to attack (success),
Orc takes damage (bite)
Snake makes free grapple check with grab (success)
Orc takes damage (constrict)
Both creatures have grappled condition now.

[Koraxs]

Thanks, guys.
I think absolutely just like you say.
But we have a dispute with players (they seems that true is 2-nd variance /snake-constrictor must make constrict just because grappled enemy make something active/)...