Hmmm, found it so far. It's really recognizable.
I should add that with my last girlfriend, depending on the way her muscles were contracting, it sometimes was hard to reach.
I did sometimes strain my fingers doing that
But it wasn't hard to find, no.
Just dig deep (
), slowly bend your fingers and you should feel something slightly spongy at some point..
There you go
Edit: Ah, you found it already.
It is easier to reach when you are performing oral as you are a bit lower then
.