[Pathfinder] Combat Manuever Question

[Retech]

So I built this druid character that was heavily based on mounted combat and archery, but I've recently abandoned my horse familliar to get a constrictor snake. Currently our campaign is at level 3, but we are going to be getting level 4 in a day or two.

So a constrictor snake has an attack which gives a free grapple if it hits, but I am often riding on the snake. What happens when the snake grapples an enemy? Does my snake and the enemy gain the grapple condition, and I do not? Does my character jump off the snake or join the grapple? Or even better, can it continue to ride the snake while it is grappling without being grappled?

It's clearly not very optimised and our group is not the most rule-savvy bunch, but I think it works well for the character concept. (Dexterity maxed out, and wisdom at 16) At least it remains relevant at low and high levels, with archery contributing at low levels and spellcasting that is starting to kick in (basically used stone call twice to knock out an entire GM encounter).

[MightyIgoo]

Common sense would say that once your snake grapples an enemy (presumably by wrapping itself around the target) it would be pretty difficult to stay mounted. I'd require a Ride check, a pretty tough DC to stay outside the grapple and still mounted on the snake, and a less tough DC to hop off. Fail the check by enough and your character gets wrapped in there with the enemy.