Fifth-grader with gay dads shamed by substitute teacher.

The boy's dads, Louis and Josh van Amstel (pictured), said school officials contacted them immediately after the incident. (Image: Facebook)

A substitute teacher in Utah told a fifth-grader the week before Thanksgiving that he shouldn’t be thankful for his gay dads.

The teacher then went on a 10-minute rant about how “homosexuality is a sin” and “two men living together is wrong,”…