Larson announced at the end of his scheduled media availability Friday morning at Michigan International Speedway that he and girlfriend Katelyn Sweet are expecting a child late this year.
"It was Dec. 29 the first time she went. Then it was Christmas, and now it is kind of back to December 29th," Larson said when asked about his girlfriend's due date. "Christmas sounds cool, so I will go with Christmas."
Katelyn, the sister of occasional NASCAR Nationwide Series driver Brad Sweet, posted a baby ultrasound photo to her Twitter account around the same time Larson told the media.
Larson, who has two Nationwide Series wins this season along with six top-10 finishes in 14 Sprint Cup Series starts, is in his first year of full-time Sprint Cup Series competition for Chip Ganassi Racing with Felix Sabates.
Larson announced on Twitter June 2 that he had purchased his first home, posting a picture of the less-than-humble abode, which is not your typical "starter" house, to say the least.
At the time, fellow Sprint Cup drivers Dale Earnhardt Jr. and Brad Keselowski playfully chided Larson about what he might be planning to keep in such a large house.
Among their "guesses": Bean bags, an 80-inch TV, an Xbox One and a year's supply of Doritos.
Larson replied on Twitter that the house would "look like a Chuck E Cheese with even more TVs in there."
But now we know perhaps the real reason he decided to go big.