Your secret is revealed

It all happens at once. John pulls your pants and underwear down and you gasp, both in panic and in pleasure as your orgasm hits you. The packer tumbles out, flopping comically. Before John has even a fraction of a second to understand what's happening or to react, your tiny, exposed cock finally erupts. A pent-up torrent of cum explodes out of you, getting all over John's arm and thigh.
"What the fuck?" he asks reflexively, recoiling. Without thinking, you rush to pull your pants back up without waiting to finish cumming, and the last few waves of cum your cock throbs out go straight into your underwear as you clasp your hand over your crotch, willing it to stop.
"I'm sorry!" you gasp, feeling your face flush red. John pauses for a moment as he processes what just happened. You want to disappear.
"So, uh," he starts slowly, his tone measured, "what's with the packer?"
"I'm so sorry," your voice trembles, "I have... I mean you saw it..."
"A hair trigger?"
"Not that."
"I didn't see much through the mother of all cumshots," he says jokingly.
"I have a micropenis," you say, not able to look him in the face as you admit it.
"Oh," he says, "that's not a big deal."
"You don't have to lie to make me feel better."
"No, I'm serious. I mean, I'm trans and I've had a lot of sex with other trans guys. Size isn't a big deal for me. I know plenty of ways to have sex without needing a big dick involved."
"Really?" you ask.
"Of course," he says, "I just wish you'd told me. I mean, what usually happens? Do you give such good head that nobody even thinks to want your dick, or do you have a dildo or something?"
"I... well, I've never done this before," you admit, "I'm a virgin."
"That explains the hair trigger," says John, grinning, "Well, if you want, I can change that for you."
"I don't know if I can," you confess, "it's really small. I don't know if it could actually penetrate someone. I bought a penis extension sleeve alongside the packer, but my dick's so small it just fell off."
"If that's the case, you don't have to use your dick if you don't want to," he says, "I have strap-ons. I could top you, or you could wear one. I mean, I wasn't touching your real dick just now, and it seems like you enjoyed yourself well enough," he gestures to the mess of cum, and you blush. It's true, the feeling of having a large cock turned you on so much it didn't particularly matter that it wasn't real.