Hah, awkward indeed. allthough I can see a perfectly good workaround to this.
"Well Dad, now that you mention it, see this toaster here?"
I guess he could adopt a kid.
Also there is the very very small possibility that he could still have a child. Remember he was in a relationship before he was hanged. Depending how for that relationship went, he might have had the chance to have one child and not even know it.
Though it might be a slim chance.
I wonder if his body still exists and thus genetic material.