When Charlie is in his kitty condo or the platform above it, he welcomes visits and will even flirt for affection. By contrast, if Garrus is on the platform, he gets feisty! Apparently the cat tower is Garrus’ Fortress of Solitude from which he surveys his domain.
Me: Hi Garrus! You look so handsome sitting regally upon your throne. *reaches up to pet him*
Garrus: Ne me touche pas!
Garrus: Because I said so! *casually grooms himself before giving me serious side eye*
NB: Approaching the Cat Tower of Sass should only be done by professionals. Beware the catitude!