He's a big strong boy - emphasis on big! So big in fact that this chocolate lab can quite easily clamp his shaft between his thick, flexed bicep and road map of a forearm and go to town on his engorged, sensitive dick, no problem!
...A skill only enhanced if he goes and gets himself corrupted by a slick, dark and lust inducing symbiote! They have a habit of getting the blood pumping and jacking up their hosts.
Here's hoping he doesn't make too much noise with his moaning... I'd truly hate for him to get caught. :P