So! Anon- to answer your question, if Cy n Tobi where to ever experiment far enough that they include a third person, said third person would quite possibly be Cyperus. (AU version of cy when his parents are Gordie and Lily)
If it were anyone else, well Cy wouldn’t be into it or very inclined to share his wigglebutt, because technically, Rus is him, just another version of him, so not so bad right? And Tobi certainly wouldn’t want to do it if Cy wasn’t into it uvu
Tobi would be far too excited to have two cy’s mkay, like he so wouldn’t be able to contain even a bit of that eagerness.