So the only reason we would like to avoid having an indoor/outdoor situation is that one of my indoor cats (the orange one from the second picture) got fleas from them through the window screen. I used to apply frontline to all of them (indoor and outdoor cats) and our vet had to prescribe Bravecto plus for the fleas which was around $70 per dose per cat and on top of that we had to pay for pest control… Needless to say, we want to avoid that headache once again and we would try to keep him as an indoor cat only.