Cleo has the logic of pretty much every other teenage girl out there. <<
I don't know about you, but the majority of the girls where I am instantly assume that you're with someone if they're of the opposite gender and they know you. Funny, isn't it! The ways of the world are strange.
And women can be gossip machines.
Besides, she wouldn't just go up to him and ask him as a stranger, pshhht...nobody does that...pfft.
...I hope, at least, ahaha.