Simon hadn't been expecting someone to know his name here - save for the folks he'd introduced himself to so far. This voice didn't match those, but it was still familiar.

...and smaller than he recalled, and tugging on his arm.

"...Yoko?!" Congrats, Yoko, he's just as confused as you. And so is Boota. The plantsuit being more modest than anything they'd ever seen her in might be a partial cause of that.