Me and my wife can't sleep since my cats started playing all night long
Last year, in October, I rescued a female kitten from my workplace, which has many cats. She took a month to be very well adapted, since she learned to follow our routines and we had no problems whatsoever.
Then, in late March, a male cat from my workplace that was very attached to me got ran over, broke his two hips, and I couldn't bear not caring for him. I got in debt for his surgery, and adapted our bedroom so he would not climb anywhere(that included removing our bed and placing in the living room), and I would take care of him, only until he recovered.
On his first week he was very quiet because of his pain, and after the second week he became active, mainly during the night. I would lock ourselves in the bedroom, while my wife and my 1st cat would sleep on the living room bed. On his 3rd week he started to desperately want to leave the room, and we started adapting them to live together.
Been more than a month since then, and both of my cats became very well adapted to each other. They play during hours at a time, and like to be somewhat close at every moment. So at this point I'm already really attached and don't want to give away the 2nd cat.
But they are playing during late night hours nearly everyday, despite my efforts to get them into a night routine. I play for nearly an hour before our bedtime and feed them with wet food after. Usually one of them is quietly sleeping with us, so the other will wake up and start teasing so they can play. They can go from 3am until 9am nonstop. Both of them are not kittens anymore, so I don't know why they have this much energy.
And this leads to my wife really wanting to give away the 2nd cat, and I desperately don't want to add another trauma to his life. How can I fix their routine to avoid this?