Dude they did it- it's a flashback
There was totally some heavy petting; but, considering Ken-chan still has questions regarding the state of his virginity, it's unlikely they went all the way. A little baffled why this one isn't a longer serial from Honma Akira :
He's has questions regarding the state of his virginity only because the parter he did it with was a man. He's probably wondering if he's still a virgin since he didn't get to insert it in a vagina
(Y) I'm surprised that some readers didn't get the joke, glad you pointed it out...
I wonder if they had sex after they kissed or was it just the uke's imagination? This has a lot of potential to be longer but I still enjoyed it. Short but satisfying.