I think it has nothing to do with denying rather it's a species thing. Demons in this setting seem to have different emotions connected to actions. For him kissing was eating, it never crossed his mind that it's something intimate for a non-demon.
There's likely other things similar to this one as well. I imagine sex isn't as emotional but maybe just a transaction/satisfaction for each others physical aspects, not like it is for humans with emotions involved (which was what made his confession really a bit dry and unbelievable to me, there was no moment in which he understood/realized what everything means to a human).
Ikr exactly
He is getting on my nerve, he keep denying it ,it feel like he just used him to satisfy himslef ..ugh.. what will he do if there someone else who smell like uke out there? Will he eat them too? (╬￣皿￣)凸