To be honest it was really great. One little thing that would've made it wonderful. If the Younger Yukio showed up and saw the Older Yukio having sex with Rin and it becomes a threesome.
There is one similar to that - it has old yukio and Rin show up and end with a beautiful sex scene literally in his face. It doesn’t include young yukio, but the ending tells us it will.
To be honest it was really great. One little thing that would've made it wonderful. If the Younger Yukio showed up and saw the Older Yukio having sex with Rin and it becomes a threesome.