It's Hard to Say Goodbye If You Won't Leave - S3-E10
Question: In this episode, Frasier is portrayed as being allergic to cats, and cannot be close to Kate's cat. What about the times when he had sex with Kate (at the radio station building, in the elevator in his building, etc.)? As a cat-owner, shouldn't her clothes have set off his allergies before?
Answer: Not necessarily. Cat allergies aren't caused by the cat's fur (so if she has cat fur on her clothes, it wouldn't actually bother his allergies). It's the cat's dander (dry skin flakes), saliva, and/or urine that people are allergic to, so if her clothes don't have traces of any of that, he would be fine. For example, she could have clothes at work she changes into, or simply keeps her clothes in a room the cat isn't around.
Bishop73