As you embrace deeply the pleasure swelling from your balls and moan even deeper; pulling on your cock at a maddening pace; you can feel your balls beginning to swell and swell beneath you. Reaching down with your other hand you grope your testicles; finding that they are now as big as grapefruits and easily still growing in your palms. You moan even deeper as you try to fight the feeling growing inside you; so much cum being produced inside the now massive sack. You can no longer even hold them; as they swell to the size of pillows between your legs; your cock now easily oozing pre-cum and making a puddle on the sofa cushion beneath you. You moan and can't stop; so horny now; and needing to fill the boy beneath you; you raise your swollen and pulsing cock head to the boy's hole and let your pre-cum pour itself onto and over the sweet winking pucker. You lick your lips and growl at the boy who is just smiling up at you; his eyes flashing with an inner-humor as if he knows something you don't. You know that what's happening is beyond reason; but you don't really care right now; completely possessed by your animal lust; you know you need to breed him and fill him full of your cock milk; and you want and care for nothing else.
So lost in the ecstasy of your sexual pleasure you again do not notice incantation or gesture on part of the young man; as you are far too captivated now by watching the pre-cum pour from your swollen throbbing cock as you lube up the boy's hole with your own juices.