Disclaimer - I don't own Supernatural and never will. No copyright infringement intended.
Author's Note - Written for comment_fic. The prompt was Bobby never regrets not having kids, because he's already got two. Hope you enjoy!
Bobby never once regretted not having kids. Besides, he has two sons - Sam and Dean. He loves those boys like they're his own. He knows the boys feel the same way about him.
So what if they don't call him Dad? That's not important. What is important is that the boys always come to him.
When Sam returned from Hell, Dean called Bobby first, crying his eyes out. And all three of them may have been crying when they reunited.
Dean and Lisa give him two grandchildren - Robert John and Samantha Mary. He spoils RJ and Samantha rotten, but no one cares.
He leaves everything he owns to Sam, Dean, and the grandchildren in his will when he dies. Sam and Dean are by Bobby's side when he dies after a battle with cancer. Sam inherits his book - and the house. Dean, Lisa, Ben, RJ, and Samantha end up moving in there.
Bobby Singer was happy during his last years alive because of his two boys and grandchildren.
Family isn't just blood, and the Winchesters and Bobby know that.