"being cheesecake" is when two people are alone together, but one person either makes or receives a phone call that lasts longer than 2-3 minutes
Excerpt from phone conversation:
---"It's really nice hearing from you, but I have to get off the phone soon, cause I'm being cheesecake."
---"Hey whats up? I'm bored... I'm hanging out with samm, but she's being a total cheesecake."