After your last session with Ruairí you gave him some homework. You told him you'd see him again when he could insert the 10 mm plug you sent him away with.
He opens the door and enters the room naked. His cock hangs down, still thick and heavy. You can see the hollow end of the plug peeking out beyond his foreskin.
You stop him with a hand on his chest. Your other hand holds a syringe full of lube. You quickly and firmly grab his dick, push the tip of the syringe into the plug and feel it squish up against his glans, the shaft of the plug penetrating deeper under your hand.
You empty the syringe into him. He grunts in surprise. You leave the syringe there, swinging.
The swinging stops as his cock stiffens, the syringe rising until it's slightly above horizontal and pulsing gently. His erection has pulled his foreskin back and you can see the metal disk that prevents the plug from being swallowed any further.
You tell Ruairí to lie on the bed. This time you'll leave his hands free so he can talk. As he lies back his cock points at the ceiling, the extra weight of the plug and syringe making it bob from side to side. You grasp the syringe and with the other hand massage the underside of his penis up towards the head, pushing some of the lube around the plug inside him.
"The plug is still a tight fit," he signs. You nod and repeat the massaging motion, ending by taking the end of the plug, turning it gently and pulling it out of him. Lube oozes out of his gaping piss-slit.
You use antiseptic wipes to clean his cock, taking care to get into the space between his foreskin and the ridge of the cockhead. More lube oozes out.
Taking an 11 mm sound you find it slips easily between the lips of his peehole but stops at the tighter spot just inside. You press gently and rotate the sound while varying the angle slightly but his cock twitches and the tip slips out.
Holding his shaft firmly with your left hand you insert the sound again and tease his hole some more. Now his dick can't escape as you probe around, sliding the tip in and out and around the navicular fossa.
You switch from teasing and apply a bit of pressure. Press and release. Press... and release. Ruairí moans each time it slides in a little further then louder as it finally slips past the tightness. You release the sound and just guide it as its own weight pulls it further in.
He stares at the sound as it slides in then looks at you as it slows and stops as it reaches the curve near his balls. About a third of it is still visible above his firm purple glans. You push his cock slowly up towards his head and then down towards his feet, causing a little more sound to slip inside and a little gasp from Ruairí.
Having found the right angle you apply the tiniest pressure to the outside end of the sound, ending with your finger pushed firmly against his piss-slit. You rub your finger around the tip of his penis, holding the sound inside until he groans and writhes slightly. Removing both hands you let his shaft spring up; the tip of the sound glistening in his opening.
You stroke the underside of his penis, feeling the hard metal below the flesh. It twitches again, swallowing and revealing the sound. "Push it out," you tell him, "and now let it slip in again". He repeats this a few times, still fascinated by the shiny metal as it emerges and disappears.