Fanboy Summoning Shafted by an Otherworldly Beast

"Welcome, my beloved priestess." Hardcore BL fan Aizuhara Kotone collides with a freight truck and wakes up in another world. If that wasn't enough, a handsome but outlandish man named Nagi appears before him and declares, "I've been waiting all this time for our wedding night to finally arrive." But Kotone only wanted to watch over his favorite characters from afar - he's not interested in starring in a BL himself! He plans to avoid ending up in a sex scene, but for some reason his body keeps responding to Nagi...?!