This is a theory I have!oh and this part is gonna be pretty short.

Remember that one Pax Prime where everyone was haywire about septiplier?
Well my theory, is that maybe,if they aren't secretly dating, they got together around that time of Pax Prime. I mean why else would they out-of-nowhere, start bringing up septiplier a lot? That was the one Pax Prime that celebrated septiplier a lot! They even hugged a lot! I think if they are secretly dating, that's the time they got together.