"Nah I want you all to my fucking self; you're fucking mine!" You roar; and smirk at the same time; you grip him around his body and squeeze him tight against you; your cock still impaling him thrusts hard and fast into him to make the point. You lick his face again; still kind of wishing you shrink down a bit so you could kiss him proper; you were wondering when it would be appropriate to ask him if he could perhaps change you back. He kisses your nipple which is near his mouth and you can feel another toxic transfer; this time the fluid was mixing with the first; it would have been deadly if you were still human; but in your current form it just made your cocks thicken and swell and engorge and feel so incredibly sensitive; you coo and snarl at the same time as you gently stroke your cock with his hole. You moan and whimper; your cock so incredibly sensitive inside him; it was only a matter of moments before you were cumming all over again; your new quartet of testicles the size of basketballs produced copious amounts of cum in a matter of seconds.
You quite literally had to fuck him like this constantly to keep them from swelling up to bursting; of course that might be part of the reason you were always leaking a steady stream of cum at this point; otherwise your new bigger sack might just explode.