I'm looking for a one-shot where the protagonist's friend told her she was a lesbian and she kinda started thinking that maybe she liked her (the friend), only to be disappointed when the friend introduced her to her girlfriend. I'm not sure, but perhaps she hang out with the friend on the rooftop...?
There was also a sequel, where I think she buys something from a vending machine and sees them passing by...? Or something. And it just remains an unrequited love.
I'm probably mixing up the details here, but that's all I remember.