When the news of the incoming Fusion Wave got out, your parents decided that the best thing to do was to split up and isolate themselves temporarily, leaving you all alone in the house.
This suited you just fine. What 17 year old guy wouldn't want the house all to himself?
Of course the first thing you did was call your girlfriend over.
You and Isabelle had been dating for a year, but because you both had overbearing and overprotective parents, you rarely got a chance to get intimate with each other. Of course neither of you actually believed in the Fusion Wave, it was just some weird internet prank that had driven the world crazy, but at least it gave you this perfect opportunity.
The doorbell rang and you quickly ran downstairs to answer it.
Isabelle looked stunning in her skinny tank top and tight denim cut-offs that accentuated her curvy hips.
She ran a hand through her long black hair and immediately pulled you in for a kiss right there, giggling mischievously under her breath.
It wasn't long before you were both undressing each other on the couch. Isabelle pulled her tank top up over her head, revealing her perfect C-cup breasts, unbound by a bra. Next she unbuttoned your jeans, freeing your sizeable cock, then slid her shorts all the way down her legs before kicking them across the room.
Before you knew it, the two of you were eagerly making love on the living room couch.
You plowed in and out of your girlfriend's wet, shaven pussy as she pulled you in for an enthusiastic french kiss, the two of you moaning in pleasure.
At this exact moment, the two of you were suddenly hit by a searing wave of heat, and it felt like you were being pulled closer, even though your bodies were about as close as two human beings could possibly get. As you kissed, your face seemed to push through hers, and you felt your lower body thrust deeper into her. Soon you blacked out.
As you awoke, you found your vision obscured by a curtain of dark hair. You couldn't see Isabelle but you heard her moaning woozily directly behind you. As you struggled to see what happened, you found that you could switch your vision to a pair of eyes seemingly on the back of your head. You found yourself looking down at a body that mostly resembled Isabelle's.
"What happened?' she groaned.
You quickly realized exactly what had happened. You had been fused together in the same position you were in during sex, however, very little of your original body remained.
Your combined form now mostly resembled Isabelle, but with a skin-tone somewhere in the middle of your lighter skin and her darker skin. Your face now emerged from the back of her head, but by concentrating you could see through Isabelle's eyes.
The only other notable change was in your lower body. Because you were in the middle of sex when you fused, your groins had fused together and your asshole had replaced Isabelle's vagina, leaving you with two assholes and no genitals.
Isabelle had control of your new body, but you could vaguely feel everything, and could still talk and move your own face.
"Are you okay, Isabelle?" you called out from the back of her head, trying to remain as calm as possible.
"John? Where are you? What happened?" she sobbed, gently touching the anus that had replaced her pussy, causing you to shudder at the sensation.
Perhaps your parents had the right idea after all.