Kiddo might be the funniest choice Rex could have gone with, as far as they're concerned. At least it's very clear by the way that absolutely impish smile remains right there on their face.

"I wasn't aware I was obligated to be helping." He's reactive and that's something they enjoy, after all. It's almost funnier than watching the toy yeet out the window, only to come right back with a vengeance. He has good reflexes, at least.

"Well," with a soft 'hup,' they slide out of the bed and onto their feet, smoothing down the nightgown they'd awakened in, "I imagine you can use it. Or ignore it, rather than rudely throwing away a no doubt painstakingly crafted gift." Excuse them just sidling up to the taller man to be absolutely unrepentantly nosy about the actual product—more to rile Rex than out of earnest curiosity. They are a little curious, though.