According to Crushable.com, the pair reportedly engaged in some PDA at New York’s John F. Kennedy airport this past weekend.
“They came over to the gate right as I was boarding and I saw him first,” an eyewitness told the website. “His hair is fuller and he’s got a beard, but I recognized him right away.”
“Then he walked over and a girl with him sat down and it was Rory f—-ing Gilmore,” the source added, referencing the name of Bledel’s memorable “Gilmore Girls” character.
Kartheiser, 33, and Bledel, 30, reportedly did not sit in first class and, instead, occupied two middle seats on the plane, one right behind the other.
“He was leaning over the back of his seat talking to her and leaned over and kissed her,” the tipster added.
Bledel first appeared on this season’s “Mad Men” as a housewife who has an affair with Kartheiser’s character, Pete Campbell.
In a Q&A with the AMC show last month, the actress said she was “really nervous” about filming her sex scenes with Kartheiser.
“(Vincent) noticed, and made it much better for me by just sort of making sure I felt comfortable,” she said. “He kind of helped me take the edge off a little bit just by being nice.
“He’s light and funny and has lots of energy on set. He keeps everybody energized as well.”