Day 2: You've got your OTP, you have to throw a third into the mix (from the same fandom), creating an OT3. Who is the OTP, and in your opinion, why would they make a perfect third for them? Bonus question: What about adding a third to your OTP from a different fandom? Who and why?
Hmm... different answers for different fandoms!
For Teen Wolf, I go between Derek/Stiles and Peter/Stiles regularly. To make an OT3, I certainly would put Derek/Stiles/Peter together. They're all broken in different ways, so even with the squicky Derek/Peter combo, they make each other better.
For another fandom... hmmm... Maybe Harry Potter to go with Derek/Stiles. Harry's just as broken and would cling to the family they offer.
For Stargate Atlantis, my OTP is John/Rodney and I have a hard time putting anyone else in there. It's easier to go to OT4 and go to John/Rodney/Teyla/Ronon but three is harder. Maybe Miko. Fanon makes her badass enough to give as good as she gets with John and Rodney, although I could consider Radek, just for the pretty!
From another fandom? Oohh... Sheriff Stilinski! He'd be good for both John and Rodney...
For Harry Potter, my OTP is Harry/Severus and I can easily throw Draco into that mix. Draco/Harry always has a potential for some epic hate-sex.
From another fandom... Peter Hale... Peter and Severus! What an interesting pairing that would be! This entry was originally posted at https://goddess47.dreamwidth.org/107943.html. Comment here or there as you please.