Dad is a bumbling doofus who acts as if he never, ever spends any time with his son and had no intention of ever having a conversation with him except dammit the car has broken down and he's trapped with this kid.
Kid is incredibly uncomfortable being with his "father," who is only making things worse by doing what only cliche'd awkward loser dads on tv do- take accidental moments of forced intimacy to try to check that "have the sex talk with the boy" box on his Parent Bingo Card. He clearly would rather be ANYWHERE ELSE but with his dad right now. And I can only guess that there's no WiFi service wherever it is they broke down, otherwise none of this would be happening- both of these idiots would be on their phones, pretending the other does not exist.
Dad is "saved" from having "the talk" by the appearance of the tow truck. Oh thank goodness, they were only seconds away from maybe having a meaningful conversation (though I doubt it. Dad's an inappropriate ass with lousy timing, Kid has or is going to learn about puberty the way all boys do- through experience, and through their friends, NOT from their dads.)
Kid has let dad know that he doesn't want to have this conversation with Dad, EVER. Dad would be wise not to share this almost-moment with Mom; she'd be totally justified in calling him a clueless moron for making such a half-assed attempt to be meaningful in any way to the kid he helped make. Go back to being silent and stupid, Dad. Kid and his friends have got this. Mom doesn't expect you to rise above your mediocrity. Just get the car fixed, drop the kid off, and get back to the office where you will be surrounded by people you can relate to. Moron.