Well first time they met are when Ino trying to kill his son (lee bin) for 'stealing' hwagok from him. Since then they somehow came to an arrangement (wasnt told how or what is it about in detail) but since then Khaki starting to meet up with Ino from time to time and it came to this type of relationship. (づ￣ ³￣)づ
DocVamp accidentally slipped and fell into Ino's bussy when Ino was trying to murder his son, oG Vamp Daddy, for stealing his "bride" OG Mama Wolf.
It happened off screen, because nobody wants to see GrampVamp have freaky doggy style sex with a werewolf 500 yrs younger. Or so they think
Can someone tell me again how Ino& GrandpaVampire started their relationship? I completely forgot abt them ┗( T﹏T )┛