Disturbing surveillance videos made public Tuesday show a Long Island dermatologist raring to party as she heads to a drug dealer’s Chelsea apartment — and an HBO producer slinking away after flagging down an ambulance crew to treat her for a fatal cocaine overdose.

In a 13-second clip shot inside the building, tragic Dr. Kiersten Rickenbach Cerveny, 38, is seen wearing a cat-ears headband as she sashays down a hallway and pumps her right fist in the air.

Trailing closely behind the married mother of three is Marc Henry Johnson, a co-producer of HBO’s upcoming fall series “The Deuce,” about the dawn of the sex industry in Times Square during the 1970s.

A timestamp on the video shows 3:28 a.m. on Oct. 4, 2015, although authorities have said it was actually about an hour later.

A second, two-minute clip shot outside shows Johnson emerging from the door to 223 W. 16th St. moments after an ambulance with flashing lights passes by.

Johnson, looking haggard and anxious, repeatedly waves his right hand and ducks in and out of the building before emergency workers arrive in response to an 8:32 a.m. 911 call.

As one paramedic maneuvers a stretcher onto the sidewalk, Johnson avoids eye contact and slips past him before strolling away.

Manhattan federal Judge Jesse Furman released the videos after sentencing Johnson, 53, to a year and a day in prison for acting as an accessory after the fact to the crime of maintaining a drug-involved premises.

Johnson’s dealer, James “Pepsi” Holder, was sentenced in May to five years behind bars.