The lascivious lovebirds who joined the “Mile High Club” aboard a Delta flight tried to cover up their activity with a blanket — as a fellow flier napped next to them, according to a report that reveals new details about their sky-high romp.

The 48-year-old woman and 28-year-old man — who were strangers before boarding the LA-to-Detroit flight Oct. 29 — were caught in flagrante delicto in their seats, where she performed oral sex on him, according to reports.

“I felt bad for the guy beside them, but I guess he was sleeping,” a passenger wrote in a witness statement, the Detroit Free Press reported.

The woman’s seat was not in his Row 26, but she switched her seat so she could be next to him.

Despite the couple’s best efforts to lie low, the “highly intoxicated” woman and her partner spurred complaints from other passengers, according to a police report obtained by the Free Press under the Freedom of Information Act.

One person wrote that passengers “went to the row and witnessed the lady in the man’s lap performing felatio. … they had a blanket partially covering the ‘act.’ I asked for boarding cards and names.”

The woman bolted right up, and the man “tried to apologize.”

The Wayne Metro Airport Police Department was alerted about two passengers having intercourse on the plane.

“Per dispatch, the female involved was reported to be highly intoxicated,” according to the report.

When the plane landed, two cops boarded. One of them spoke with the man, who said the woman “had fallen asleep in his lap but that they did not have intercourse.”

He claimed he only “grabbed her breasts on the outside of her clothes.”

An officer then questioned the woman, whose eyes were “bloodshot and red.”

She mouthed off loudly as she and the man were hauled off in cuffs to an airport jail cell, according to the report.

Police allowed both passengers to get their luggage — though the airline refused to rebook the woman’s flight, saying she was “not permitted to fly Delta,” according to the Free Press.

She left the next day, on another flight, without incident.

Police said the two were issued citations from the FBI for lewd and lascivious behavior and for disorderly conduct.

The Free Press did not identify the couple because they were not charged.