Cain does eventually notice their antics, when Nemu gets so into it that only one of them is playing a combat buff.
"What are you doing? Stop stealing Misha's spot and get back to casting. You can take the other side if it means that much to you." He says, thumping the Felian on the head before petting her ears and returning to the fight. The happy look on Misha's face doesn't go unnoticed by the other ladies who share a meaningful glance at the two.
Mythryll knows they've casually shared a bed more than once in every sense of the phrase, but now that she has a rival, the laid back cleric seems determined to move things into a more solid direction. While Nemu is sweet and cuddly in her own way, the Mage is still cheering on Misha's chance to land herself the man she wants once and for all. Now that she's finally decided to make her move that is.