Because I still occasionally get comments about this: Unfortunately, no, there is no (and there will never be a) sequel to this fic.
However, due to demand, there is a smut behind-the-scenes sort of companion fic called Behind Closed Doors. It's basically scenes that didn't make it into the Friendly Competition narrative, or which didn't get delved very deeply into, or scenes from different perspectives.
As of right now, it has 5 chapters up, most of which are pwp. There are warnings at the top of each chapter which will tell whether it is pwp, or, if not, will tell when the smut begins so that you can skip it. Chapter 5 (The Forest) does have a few content/trigger warnings, but I believe it will be the only one to require any (and, of course, they are listed at the top of the chapter).
Final note on BCD: it is not currently being updated, and has not been for nearly 2 years. It is not abandoned, and will eventually be finished, but it will likely continue to be quite some time before it is updated.
If you are interested in reading more works from me:
I do have more Harry Potter (specifically only Drarry, as of right now) content.
—We Can Call It Paradise: 5.5k word ficlet
—Extruendam Eam: Eighth Year fic dealing with PTSD and depression; 12k words, NOT complete on indefinite hiatus
—I'll Play Your Game: fake-dating fic; 52k words
As for other fandoms/ships, I have
—As The Fragments of My Skull Begin To Fall: 1k word MCR (Way brothers) short story about suicide [RPF, so only on AO3 and Wattpad]
—The Aftermath: 1k word NBC Hannibal oneshot; a follow-up to another Hannibal oneshot
—Loud Music: 1.5k word Phan oneshot that I very much do not recommend reading but keep up for some reason [RPF, so only on AO3 and Wattpad]
—Lie To Me: 4.5k word Supernatural (Sabriel) ficlet; they have a really unhealthy relationship and Sam is obsessive
—Ever Since We Met: A Supernatural (Sabriel/background Destiel) fic about the years after the Elysian Fields Hotel, and my take on Gabe resurrecting (written pre-S13); 11.5k words
—Begrudging Affections: JayDick rom-com ficlet; 14k words
—An Awfully Big Adventure: Larry Stylinson Peter Pan AU; 27k words [RPF, so only on AO3 and Wattpad]
—Steady On Forward: A Nightwing-centric JayDick/Batfam fic centred around love, family, trauma, and healing, so mind the warnings; 94k words
And, of course, I have more fics in the works, including more Drarry, Hannibal, Sabriel, and Larry, and all sorts of other fandoms/ships/OG works (I now have less than 30 WIPs, but I'm still a mess).
Thanks again for reading!