Goofy is the only original Disney character who does not have a girl like Mickey or Donald, but he's the only one who has a son, Max. It's not the fact that he had a son (possibly out of wedlock), it's the idea that Goofy actually had sex with a woman that keeps me up at night.
Actually, Goofy was paired with Clarabell at one point.
In the '50s era "Goofy the everyman" shorts where Max originated, Goofy actually did have a wife, but she (and all other female characters) was The Faceless.
It's alluded to in A Goofy Movie that he is a widower, if that helps.
To answer all of the above, Maximum "Max" George Junior Goofy's (yes, that's his full official name) mother is most likely Penny Libertybee, from the Minnie 'N' Me franchise. She looks just like the faceless Mrs. Goofy would have looked: same red hair, same nose, etc. However, there was also another character from the comics called "Glory-Bee", who some say is the same character as Penny, and she did have red hair in at least one comic, but in most of them she was a blonde. Anyway, the major Goofy fans who keep track of the family trees have said that Max's mom was most likely Penny, but could have been Glory-Bee, or both if they were the same character.
I recall an episode of Bonkers that stated Toon babies come from a Delivery Stork. Goofy's a Toon, right? There's your answer!
This can be explained by a little judiciously-appled Tiny Toons physiology — i.e. laughter (or rather, mindshare) keeps a toon young (or rather, at their "iconic" age). People know Huey, Dewey, and Louie as 10 year olds, so they stay 10 year olds; people don't really know Max, so he ages normally.
Relatedly, there's also the fact that the people who do know Max are already used to him aging normally.
Disney went out of the way to make Mickey Mouse and friends, plusOswald, popular again and succeeded . But why haven't they done anything else with them? The only thing they confirmed was Epic Mickey 2, Seriously the only thing I want is announcement for a new Mickey Cartoon.
They may still be thinking. Of stuff to do with him? Or they want it to be a surprise?
Actually, there's 1 Mickey Mouse Movie in the works, with hints at a 2nd movie being made starring Mickey Mouse and focusing on Disneyland. And these two films aren't straight to DVD or anything like that, no, these are the Real Deal. Hopefully, Oswald will get a Short before the actual Film.
He appears in Get a Horse! at the very end as a cameo.