But from the looks of things, the 32-year-old reality star had a lot on her mind.
Wearing a sweatshirt, black jeans, boots and sunglasses, Kourtney appeared glum as she left a restaurant in Calabasas, California.
Not missing a beat: Kourtney Kardashian brushed off her family's troubles and went on a lunch date today with boyfriend Scott Disick and son Mason
The brunette beauty, who is due to give birth to her second child in the late spring, announced her pregnancy in November.
Kourtney and Scott put on a brave front this afternoon as they coped with the controversy surrounding her mother and late father and sister Khloe.
Earlier this week, her father's ex-wife, Jan Ashley, claimed that Robert Kardashian is not Khloe's biological father.
Eating for two: Kourtney is believed to be about four months pregnant with her second child
'He would never say in court documents that Khloe wasn't his,' the divorce lawyer's second wife told RadarOnline.com.
Jan broke the news to Star magazine, which was corroborated in a separate interview with Robert's widow Ellen Kardashian.
Doting father: Scott held little Mason close as they left the restaurant
Trendy tot: Little Mason wore trainers to match his sweatpants
However, Khloe has openly spoken out about her doubt at being a true Kardashian on her E! reality show.
She has never taken a DNA test with her siblings to determine the truth of her paternity.
Both Jan and Ellen see Robert's alleged cover-up as admirable, saying he did not want to hurt his beloved daughter Khloe.
Shopping therapy: Kim Kardashian got in a bit of shopping today, despite the controversy dogging her family