This is normally a precursor to having children! Male cats even when neutered will fight and spray all over the house. Male cats are usually more affectionate than female cats. Both male and female cats will destroy the house in a matter of months. Our male cat died last year still miss him but after 14yrs of spraying and shredding the sofa’s I would never get another one. That’s not to mention the once a month trip to the vets to get him stitched up and antibiotic jabs. Our female cat is 13, she has spent the last 12 yrs bringing in dead and alive birds, rats, mice, voles and coy carp! She is a one cat urban wildlife killing machine. For this reason mainly I would never get a cat again. I’ll miss her when she goes though. You have been warned! As for cat flaps if I had my time again I would build a cat shed in the garden and let the cat in and out in the morning or in the evening. If it rains or its cold they could stay in the shed till I let them in. Cats are wildish animals and are tough as hell.