Cat is really quite buff. As he strides around, you can see the definition of his muscles, clearly highlighting his strapping physique, as if he’s just emerged from a gym. No question about it, his gym is our flat. And now Cat has taught Kitten how to turn our home into a fitness center, a place in which all kinds of death-defying extreme sports can take place.

Cat’s favorite activity is parkour. The way furniture of different heights is laid out in our home happens to be perfectly suited for this. Kitten, being much smaller, isn’t able to jump as high and can’t come close to matching his prowess. And so Cat jumps alone from the top of one cabinet to another, moving with speed and precision with an awesome variety of postures. Husband and I watch with our hearts in our mouths. We’re not worried that Cat will slip and hurt himself, more that he will knock over the vases or glassware in the cabinets. This has happened more than once: Cat sending an ornament I particularly liked crashing to the ground, where it shatters into tiny pieces, as does my heart.

Cat feels no shame about these incidents—in fact, he’s proud of them. Whenever he reaches a spot that’s particularly difficult to get to, he’ll perch there for a while, gazing down at me with a look of superiority, the unmistakable air of a champion.

What with his innate sense of control and balance, Cat was born to be a parkour star. I’ve never seen him miss his footing. Occasionally, human beings get pulled into his obstacle course: Husband and I find our bodies being treated no differently than wardrobes or chairs. We’ll be sitting on the couch or asleep in bed, completely unprepared, when the kitties suddenly spring onto our bellies or chests, inevitably Cat followed by Kitten, a one-two punch, heavy followed by light. Before I even have a chance to cry out “aiyoh,” the kitties will have made their escape.

Kitten may not be as good as Cat at parkour, but she can more than hold her own in drag racing. The two of them turn the smooth tiled surface of our living room floor into a racetrack with their own bodies for cars, their legs turning into wheels. Having marked out their course, they’ll pretend to be chasing each other and playing around as usual, all the while charging straight ahead, one behind the other. Halfway down the living room, their legs stop moving and momentum alone carries them forward round a bend in a perfect C-shaped arc. Then they race back to the finish line for more speeding, cornering, drifting.

Cat and Kitten have so much fun that I can’t help but join in. I’ll grab a sheet of tissue paper, wad it up into a ball, and fling it from one end of the living room. The three of us go chasing after it, slipping and sliding across the floor. No matter how many rounds we play of this game, I always come in last.