Thread: Sudden Behavior Problem with Brother/Sister Coons

We have two Maine Coon cats from the same litter; a brother (neutered) and sister (spayed). They've been great companions for over a year since we got them from the breeder. They are both house cats with little regard to going outdoors. However, the male did venture away on Sunday morning when the front door was left ajar. Several hours later he showed up on the opposite side of the window looking at his sister as if to ask her to let him indoors; like a sailor coming off a night of liberty. He was filthy, having been in our wood behind our home, so we promptly bathed him. Since his return and after the bathing (and for two days going...) the female sister has begun 'hissing' and vocalizing as if to attack. She avoids him and he looks at her as if he doesn't understand the rub! Though funny at times, it has become a concern. Does anyone know why this odd behavior by the female has begun and persists. It's as if she's forgotten who her brother and pal was and is dealing with a stranger! Stumped in Indiana