1. Uncle Misha appears randomly when your character is walking around outdoors with cum on her face. He comments upon it. Something like "It looks good on you" or "Again! At least you're keeping busy"
2. Uncle Misha also appears randomly at the Diner where the Mom works. I think he can only be there in the afternoons (14 to 18?) but haven't checked that. He will ask your character to walk him home. If you agree, he has sex with your character and pays 500. (This is kinda weird, because - while I probably don't read as carefully as I should - I had no idea she was agreeing to prostitution when agreeing to walk him home from the diner.)
2a. After that you can go to Uncle Misha once per day (evenings before 00:00) to have sex and he'll pay 200.
3. You can also run into him in the stairway of your building sometimes. If your character has had sex with him before, but not yet that day, he'll offer something like 50 for a blowjob. After getting 50 for the BJ you can still go to his apartment for the 200 sex.
4. Uncle Misha hangs out with your stepfather at his garage. If you've been naughty, Uncle Misha might tell your stepdad about it, and they might decide to punish you...