Hi, I read this manga a long time ago so my memory of it is pretty blurry.

It might have been a oneshot or part of a collection of oneshots, and it could have possibly been smut or at least from what I remember it was slightly on the mature side.

The plot had to do with a girl who met up with her friend after a long time. The friend used to be fat, I think, but is good looking now and even has a boyfriend. The three of them (the mc, the friend, the boyfriend) end up getting along really well, so they hang out a lot at the friend's apartment. The mc and the boyfriend start to develop feelings for each other. I think the friend started to notice, so at one point, she tries to have sex with her boyfriend in front of the mc and the boyfriend gets really mad and tells the mc to get out. The friend and boyfriend eventually break up (due to other problems) and the friend finds a new boyfriend. Later, the mc wants to know what a kiss feels like so she asks a random guy to kiss her. Said random guy brags to the boyfriend that he kissed her and the boyfriend gets pissed. The two get together at the end of the manga but I can't remember any specific details about the ending. Also, one minor detail, the mc started out with really short hair and started to grow it out as the story progressed.

Sorry for such a shitty summary. I will be so impressed and eternally grateful if someone can help me find this. Thank you!