A Washington man whose sick texts about molesting children were spotted by a fellow airline passenger was sentenced to 15 years in prison.

Michael Kellar, 58, was texting his girlfriend Gail Lynn Burnworth, 52, while on a flight to San Jose in 2017 when a hawk-eyed passenger saw the disturbing messages on his cellphone, according to a press release from the US Attorney’s Office in Washington’s Western District.

The concerned traveler told authorities that a man sitting in front of her was texting about the abuse with a large font on a large smartphone.

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This AUG. 3, 2017, file photo released by the San Jose Police Department shows suspect Michael Kellar, a resident of Tacoma, Wash.  (San Jose Police Department via AP)

“I commend the airline passenger who spoke up about the disturbing texts she witnessed on her flight,” US Attorney Brian T. Moran said in a statement. “We all have had that moment when we question: ‘Do I get involved.’”

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In the text exchange, Kellar and Burnworth talked about using Benadryl to drug and rape two of the three children, aged 5 and 7 at the time, who lived with Burnworth.

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The observant flier snapped a photo of Kellar’s phone and reported it to flight attendants, who alerted cops in San Diego — where Kellar was questioned and arrested.