The source of the rumor is the Left. Hillbag paid for the Dossier. Obama and his deep state officially verified it, knowing it would inspire all kinds of speculative narratives for the DNC owned SS Media
The fairy tale goes like this ...
Vlad invited Cohen to Prague ... where the KGB showed the peepee tape to Cohen. Then Pootie threatened to release the tape, supposedly showing to hookers peeing on a bed that Obama had slept in, ... which the SS Media then morphed into ... a tape of DJT being peed on by two hookers.
So Pootie, via Cohen, is blackmailing DJT into doing Pootie's bidding. For now, the peepee tape resides in a secret Russian KGB vault, waiting to released the moment Trump disobeys Putin.