One of Michael Jackson‘s doctors had a famous guest on his yacht Tuesday — Michael’s son, Prince Jackson — and they were sharing a hand-rolled “cigarette” and passing it around to various people on board.

The doctor — Alex Farshchian — had a complicated relationship with Michael. According to a letter he wrote to Michael — seized by the Santa Barbara Sheriff’s Dept. in MJ’s molestation trial — the doctor was trying to get Michael off Demerol and onto a synthetic, less addictive substitute for the drug.

That’s why the photos are so interesting … the doctor who was treating Michael Jackson in the throes of his Demerol addiction was smoking something with MJ’s 18-year-old son.

Dr. Farshchian tells TMZ they were smoking tobacco on the yacht in Miami. It’s odd that a tobacco cigarette was passed around to at least three people.