Hello!
In this manga i am looking for is part of the extra/side pairs of the main story.

It initially started with the uke getting drunk bc he was helping a junior by drinking his share. Then the uke's 2 friends helped him back to the dorm and iirc they had sex.

Then i think the next day or something the junior had like an admiration for the uke and somehow ended up outside the uke's dorm and saw the uke and one of the uke's friend having sex. Then the uke's other friend came up to the junior and asked if he wanted to join? Or something like that. So they ended up in a foursome.

If you can help me find this manga that would be greatly appreciated! Thank you