(GRSSS) Gay Random Sexual Short Story #1

This is a made up story, I tried to make it as realistic as possible. Two cousins fuck... you got a problem with that??? Anyways, a young teen is taught by his cousin to prepare him for the test, but the teen almost learns nothing because underneath the whiteboard (in the teen's house) is a big mysterious bulge that distracts him. The day has come where the mystery on the teaching cousin's bulge is revealed.