Sean Penn shares his snow cone with Charlize Theron's son Jackson at the generationOn West Coast Block Party in Los Angeles on Saturday, April 18. Credit: Imeh Akpanudosen/Getty Images

Sharing is caring! Sean Penn had an adorable day out with his fiancée Charlize Theron and her son Jackson, 3. The trio hit up the generationOn West Coast Block Party in Los Angeles on Saturday, April 18, where all eyes were on them. 

But instead of preening for the cameras, Penn, 54, and his pal Jackson seemed much more invested in the snow cone selection at the outdoor event. Theron’s son snagged a red cone while his stepfather-to-be picked up a blue one. 

An eyewitness said they seemed to be having a passionate discussion about the frozen treats when Penn let the little boy have a lick of his flavor. The insider said the two gents then started sticking their tongues out at one another to show off the brightly dyed colors. 

Theron, 39, spoke at the event, honoring her friend Ari Emanuel, and Penn was on Jackson duty, pulling out a Transformers toy to entertain the tiny tot. 

“Sean is very clearly fond of Jackson and they were acting like a happy little family,” the eyewitness told Us Weekly of the event. “They were like each other’s little buddies.” 

Theron and Penn secretly got engaged in November 2014, but have been friends for years. 

“I think our friendship stemmed from mutual respect -— more on my end, because I really didn’t have a body of work 20 years ago, but my love and passion for making films —- that was our common ground,” the Dark Places actress explained in the March issue of Esquire