The mirror comment, especially the admiring yourself in the mirror part, reminded me of this funny guy I knew when I was growing up, nicknamed Doggy.
It was somewhere around 2003 I think, so these guys were aged 14-16. Two of his quite close friends were out for a walk, and about to pass Doggy's (not yet known by that name at the time) house. Knowing he was in possession of some cigarettes, they decided to ask him if he wanted to hang out and maybe share some ciggies with them, but instead of walking to his house and ringing the doorbell, they called him on their cell and asked him to walk the two blocks from his house to the street the friends were at and meet up. Apparently he wasn't in the mood for hanging out, possibly even detecting these guys mostly wanted his company for the cigarettes, and told them he won't be joining them because he needs to "walk his doggy". The friends persisted for a while, asking why won't he just walk his doggy to where they are and have a cigarette with them. But he didn't give in, and they ended the phone call. It was this decision not to share with his friends that ultimately lead to Doggy having his reputation somewhat mangled for at least the rest of his youth.
After a while the two guys decided to walk to Doggy's house to bum some cigarettes anyway, no matter if he'd hang or not. When at the house, they rang the doorbell a few times. As there was no answer, they thought he must still be out walking his dog. As they're about to give up and leave, the other guy randomly decides to quickly peek in through the kitchen window, through which there is a direct view to their hallway too. Finns take their shoes off when indoors, so I guess he just wanted to see if Doggy's shoes were where they usually would be and if he was indeed just hiding from them, not wanting to share his cigarettes. In the hallway there was also this huge wardrobe for jackets with two sliding doors, both doors having mirros on them, spanning the full height of the doors.
What he saw was not Doggy's shoes, but Doggy himself on the floor in front of the mirror, on his back, curled up like a shrimp, desperately trying to get his erect penis reach his mouth, every now and then taking a look in the mirror to see how close he was to getting it in. They rang the doorbell a couple more times in absolute disbelief (the actual words they used when describing these events to me later on), but Doggy didn't react, he didn't stop. He was seemingly very persistent on getting his own penis into his mouth.
The friends finally left and eventually met up with other friends to whom they told what had happened. Obviously in school, which I think was the most populous middle school in Finland at the time, the story spread with great speed, with the principal and teachers trying their best to curb the spread of the story, afterwards labeled as an atrocious lie concocted by these two friends with whom Doggy wasn't willing to share his ciggies with.
I never really spoke to Doggy after that. It felt genuinely surreal somehow seeing him cope with this thing. I mean there were people in all the surrounding big towns that knew the story and would greet him by calling him Doggy, even if they didn't personally know him.