HELP!

Okay so I am in desperate need of help in searching for a manga! The reasons are unimportant. But I remember lots of details for anyone that wishes to help. Ofc I can't remember details down to the letter but some that could help.

All I know is that it was definitely a Free! Dj (Doujinshi) and that there were two couples. Since there are technically five of them (Rin, Haru ,Makoto, Rei, and Nagisa) I don't remember the pairings exactly. However, I do think it was Haru x Makoto and Rei x Nagisa. I also think it was a one shot.

As for the contents, they two couples do the do practically side by side and I distinctly remember that the top of the first couple (I think was maybe Makoto) poured water on the bottom (I think was Haru) so he could climax.

Help is greatly appreciated!!!!!!