Condoms. I knew I'd forget something. (Not that Folken would have any on hand.) This is why I prefer females. I don't have to worry about getting pregnant from YOU.
Folken is a Fanel to the core, despite his sense of self-control. And if Van is anything to go by, Fanel means passion, right up there with Elric. :D Celena just happened to benefit. Twice over (it's almost a shame this isn't canon to the Nexus, because it'd be funny).