[He's willing to provide something in turn already, but he's still not expecting the compulsion that grips him and doesn't let go until he's said the three things.]

I nearly got the Doctor killed because I'd not said where he was.
I've never seen a unicorn.
I dressed up as a woman guard while we were in a prison in space, just so we could get our clothes back.

[Jamie grimaces after he's done.] I think I see what ye mean about being compelled.