"I hear you." Buffy knew that Carlos wasn't in her same world, they would have definitely been aware of the other organization. Ethan Rayne would have for sure been on the Wizard Council radar as would a Hellmouth if not the Slayer. So she wasn't under any illusion that what she had with Carlos was long term, but she did want to remember it when she got back to Sunnydale. That would suck.

"With your mind magic, do you think you could make sure we keep the memories?"