The Instagram almost certainly belongs to Dancer Asher Kane, judging by the number of videos of him with his leg over his head spinning on one foot, or leaping in the air, or similar. Dancer Asher Kane was also Lev's boyfriend, as there is a video of him tossing a laughing Lev in the air and catching him.
Asher Kane posted a lot of shirtless gym selfies, from which Martin can learn that Asher has enough muscle definition that you could use him as a teaching tool for an anatomy class. Asher also went to quite a lot of parties and nightclubs and events with a variety of extremely fashionable and attractive people. Both of those pictures usually have dozens of comments. In defiance of all concerns for his personal safety, Asher Kane attached strings to something, lit it on fire, and spun it around in circles, somehow without hitting himself in the face and causing third-degree burns.
Lev isn't in any of those pictures. There's one picture of him sleeping on what must be Asher's thigh, and another picture of him reading a book, but either Lev didn't go to parties or he was very camera-shy or both.
Asher has tagged another Instagram account, knowledge-is-prediction, in a lot of extremely sentimental pictures-- ones with sentiments like "isn't it amazing how people can feel like home" and "I tried counting the freckles on your skin but lost count every time because I found constellations on your body" or "I find pieces of you in every song that I listen to." knowledge-is-prediction comments on these with 🙄 or ❤️ or sometimes, when the spirit particularly moved him, ❤️🙄.
Asher Kane went to Burning Man! Here he is next to a Tesla coil. Here he is next to a giant sculpture of a psychedelic lion. Here he is spinning the fire things again. Here he is grinning in a floofy skirt. Here he is in the orgy tent. Here he is with one arm around an excessively handsome naked man and one arm around an excessively beautiful woman who has misplaced her shirt.
knowledge-is-prediction has commented on every single one of the Burning Man pictures with sentiments like "I don't have playa foot" and "my tent did not go cartwheeling down the playa like a tumbleweed. I in fact am currently staying in an apartment building. With air conditioning" and "I was not sexually harassed by a naked woman rolling on molly" and "I went out and bought food. With money. As we normally do in a capitalist society which takes advantage of division of labor and gains from trade."