[The Gravity Falls people are trying hard to rescue them! If they defeated some guy named Bill, and dealt with zombies and other stuff, they should manage to find a way somehow. That's why he asks:]

I know you and I aren't close friends or anything like that, but when they come to rescue us, could you make sure Basil and I aren't left behind? I don't know what we'll be doing when the rescue team arrives, or where we'll be at, but we're so small it'd be easy to not notice we're not with the rest.

[He looks away]

It's just that I'd feel calmer about everything if I knew for sure I wouldn't be forgotten here.

[And since Basil is in the same situation, well, why not to ask the same for him, as the only other person of the same size? People in the same situation must take care of each other!]