No, it is not appropriate. Such stories involving family members in an overly intimate or improper context should be private and not shared publicly as it goes against social and moral norms.
One time, my best friend sat on my lap during a car ride through a beautiful mountainous area. The view was breathtaking. With her on my lap, we shared our thoughts about nature and how lucky we were to experience such beauty. We also took some selfies together which always remind me of that special car ride.
It can be really funny. Once my best friend sat on my lap during a car ride because there were no other seats left. We were both laughing so hard that we almost made the driver lose control. It was a moment full of pure, innocent joy and silliness.
No. Such stories, if they involve inappropriate or private family moments, should not be shared publicly. Family situations are often private and should be respected as such.
By setting clear boundaries within the family. Everyone should know what is appropriate physical contact and behavior. For example, parents can teach their children about personal space from an early age.
No. It is extremely dangerous. In a car, everyone should be properly seated in their own seats with seat belts on. Sitting on someone's lap doesn't provide the necessary protection in case of an accident, and it can also be a distraction to the driver.
One story could be when I was little and got hurt while playing. Mom sat on my lap to clean my wound and tell me it would be okay. It was a really warm and reassuring moment.
There was a time when we were waiting for a bus in the cold. Mom sat on my lap to keep me warm. She wrapped her arms around me and told me stories to pass the time. It was a cold day outside but so warm in her embrace.