Good man - he deserves keeping - We had Holly from a Vet's loft - that is where they kept their rescue cat's - she had been there for over 12 month's and she settled down well although she didn't go out much but she knew she had a home - Then Ronnie appeared ( around 2015) which put her nose out of joint - Today she still tolerates him but won't connect with him - He on the other hand would love to cuddle up to her - in the house she is queen but outside is his domain - many a time he has hid behind a stem of grass and ambushed her where upon she rolls over with all four legs in the air and claw fully extended. I am sure Millie is a bit more tolerant (I hope so anyway) and you will find they settle down well together.