So since tenna is first introfuce at the start of chapter 3 of deltarune he mentions 'mike' but who is he? Well in chapter 4 [i think] there is a secret boss [idk if its consider a secret boss] were we fight three mikes but at the end of the fight none of them are mike,so who could it be? Easy,tenna and spamton child,i mean think about it,who else would recive so much love and attention from the audience than the host [or celebrity] own kid!,plus during tenna's mental break down after the end of round 2 when everyone leaves him tenna is more worried about mike leaving than anybody else,it would makes sense that mike might be tenna's kid because who else wouldnt feel scared of losing their own kid?