On the one hand, snakes have no external genitals, but on the other hand, that doesn't mean they can't violently enter you.. Also, they're cold blooded in more ways than one.
As for the gorilla, they're a monogamous species, very social, fiercely protective of their loved ones but nowhere near as terrorial as a black mamba and look like they'd be great at cuddling, so I'd say that the choice is clear..