Annie had me all to herself for over a year. I was warned that she might not like sharing me and that cats, perhaps especially female cats, don't like other cats or sharing their space. I didn't even want another cat, much less two. However, I was out a lot and she wanted to play more than I could keep up with. So I took the risk of bringing her siblings. I figured if she didn't take to them, they'd have each other and I could stay focused on her.
I had gone to the shelter to meet a different pair of kittens, but it was Boris and Arlo who captured my heart. Arlo reached beyond the cage to pet my nose and Boris gave me eye contact like a long lost soul. They also seemed super-well bonded, never leaving each others side and each exploring whatever the other one had discovered or tried.
Trouble was, someone had claimed them already! I gave her my number, saying that if they didn't work out for her for any reason, to please call me. An agonizing 48 hours later, I was taking them home from her house, thanks to her boyfriend being allergic!
Boris and Arlo are fearless. I gave them the living room. Annabelle was furious and I spent about ten days convinced I ruined all lives concerned.
Six months later, though Boris and Arlo remain deeply bonded, and Arlo eats first without fail, the three cats play and often sleep together, they share spaces, toys, litterboxes, and me without any feeling of competition or anxiety.