Okay, so Stephen's used to seeing that younger alternate around the Cooper house, but he still finds versions of his boyfriend that aren't his boyfriend quite undeniably weird. (Not to mention awkward! There are bits of his brain he has to lock up a lot that don't really care about alternate universes. There's a reason he avoids the boy and his girlfriend.)

(Fortunately, a lot of those bits are hiding. Scary alterna-Gabe is scary.)

Stephen's hands, automatically and half-unconsciously, go to the straps of his jetpack. That's where the controls are.

"I know you, eh? A -- a different you."

It should be noted that he's trying not to sound frightened. You know, just like he was trying to fib earlier.