Despite what Ty had said about this transformation not being for kinky sex, he'd wanted Lisa to enjoy it. Similarly to what he'd done for her in some previous inanimate, or near-inanimate, transformations, he'd done this one such that she'd get pleasure, even sexual stimulation, from being used. As a mouse, from being rolled around on a surface, and having her buttons clicked.
At first, using her with his laptop, he just checked on social media, and doomscrolled a bit. Then it occurred to him that this probably wasn't enough for her to experience the full potential of her form. He started up a first-person shooter game, and while he'd normally mostly use keyboard controls, he made a point now of mostly using the mouse.
After he played through a half dozen levels, he thought that she must have gotten a pretty good workout, and was curious as to how she felt. He quit the game, unplugged her cable, put her on his bed, and transformed her back to human form.
"That was nothing like I expected," she said. "When you said you wanted to turn me into a mouse, I was thinking of a small rodent."
Ty replied, "You can try that, too, if you like. But what was it like being a computer mouse?"
"I don't think I was conscious immediately after the transformation," Lisa said. "The first thing I remember was waking up to an unusual sensation, and not knowing what it was, but I think it was when you plugged me into your computer."
"How did that feel?" Ty asked. "Was it nice?"
"Mostly just a strange feeling," she said, "Maybe a bit nice. It passed quickly. I didn't yet know what I was, other than not being an animal. When you started rolling me around, that felt quite nice, but it wasn't until you clicked my buttons that I realized what you'd turned me into. I couldn't tell what you were using me for, but I enjoyed being used.
"Then you started using me more vigorously. and that felt great. You'd said this wasn't for kinky sex, but when you rolled me more rapidly, and clicked by buttons more frequently, that quickly brought me to orgasm. As you kept it up, I went into a continuous arousal and had many orgasms, up until you unplugged me, and I fell asleep again.
"So what were you using me for?"
Ty explained that he'd doomscrolled, then played a game.
"If we do this again, after the game, please go back to doomscrolling or other gentler activity for a little while," she requested. "It would be nice to cool down for a bit, rather than ending abruptly."
"Oh, sorry," Ty said, "I should have thought of that."
"No, it's fine," Lisa said. "You didn't know, and it didn't hurt me or feel bad. It's just an idea for improving the experience next time.
"Now," she said, "How about letting me try the form I _thought_ you were suggesting? How about making me a _real_ mouse?"
"As you wish," Ty said. Lisa shrank and transformed again.