[Dave's PokéGear is set to match conversation format unless he chooses otherwise, so this time she can see him when he laughs again, voicelessly, through his nose.]

Okay, okay. It's really not that difficult a concept, though. Time travel only causes a paradox along the alpha timeline if it instigates a contradiction, right? Like if someone went back from the future to, I dunno, stop their parents from porking and conceiving them. It wouldn't work because from that future's point of view, the parents have obviously already boinked. But if our Marty McFly went back and either didn't affect things or put into motion events that were supposed to happen, then it's fine even if he goes back to a time where he already exists. You see? So John and Baby John can chill together because, from John the elder's point of view, they already did when he was Baby John.