Thanks for your reply Dan.
In the link they refer to the phrase "uncovering his father's nakedness" as a term which likely represents him copulating with his father's wife/women/harem. They use this as the explanation for why Canaan the son of Ham is also cursed since it is implied that Canaan is the offspring of Ham's violation.
I guess it depends how you interpret the phrase "uncovering his father's nakedness" since either way it is not literal.