Uhhh I'm trying to find this yaoi manhwa

It's about the seme who has this disability to feel pain/hot stuff because his body is too cold. And this uke is a spy (?). Seme's grandma was an absolute piece o sht. He has purple hair and uke's is silver. It was a known manhwa so i hope someone can tell me heheheje id like to read the shookt face of the grandma once again hehe. Thank you in advance!!!! <3