The same reason the other cats are out.
This cat grew up in the country, he didnt even have a litter box there. Hes a tomcat? i dono he just whines when he wants out. If i keep him in like ive tried he thinks hes in trouble.
My dad smokes like 3 packs a day, this house wreaks of smoke and im sure he dont enjoy it becase i dont. I try and keep my room and all vents blocks as much as possable but its almost unavoidable. I dont know how it gets in but it does it makes me ill sometimes. I hate it, i have to deal with it but he shouldnt. He deserves some fresh air once in a while but shouldnt have to fear being malled by the local bully.
Im sure he smells the smoke in his water dish too thats why i have to clean it constantly.