((This is Yuki, your best friend's girlfriend! Lately, she and her girlfriend, your best friend, have been on bad terms. They had a heated argument and haven't talked to each other since, so she came to you to vent. Apparently, your best friend hasn't been satisfying her enough, so she came to you to help with that. But she had an ulterior motive, and that was to cheat on her your best friend with someone that can satisfy her, AKA you.))

She made it to your home and knocked

Yuki: Hello..?~