It was a flashback
Like before he started "dating" the uke?
Yes. Tamaki is one year older so when he started highschool, Shii decided it would be a good opportunity to put some distance between them and get over him since his love was unrequited.
So he pretended to be a college student and met Takumi (a real college student) via a dating app. They became sex friend and it lasted for about a year. They broke it off because Shii realized he was still in love with Tamaki and Takumi could never be a replacement even though they look similar (it's because their personalities are complete opposite too). So when he also started highschool he reunited with Tamaki and decided to be close friends again. But as we know they became something more.
OMGGGG. I would never know if you hadnt explained it. I felt relieved for some reason lmao thanks
You're welcome. And the reason they're still meeting up in the present is because they're still friendly. Taking to him also helps Shii because Takumi can give him advice about Tamaki since he's older and has more experience in both love and sex
But that's all it is, Shii is faithful to Tamaki. He even refused Takumi's invitation to have sex again because he only wants to have sex with Tamaki now.
that happened during the one year when Shii wanted to give up his feeling (the “rebellion” year). But then he went to high school and they met again and that’s why Shii said he’s back to square one
I was so startled when he went and find a "substitute" it felt so sudden. Is that supposed to be a part of something in the future or just something that passes by?