Sans wasn't alone in being perfectly content to stay out of that business. Bumblebee was perfectly fine with the role that he had been given and didn't really seek to "improve" his lot. Being a stealth operative was comfortable, familiar. Watching people and trying to ascertain their motives was much more fun without politics involved.

It was something he hadn't really done proficiently in some time. Thus Sans was, at the very least, a nice change. His face was unreadable, sure, but Bee mostly just chalked that up to barely having one. It wasn't unlike many individuals of his own race that liked faceplates or had to endure empurata. Regardless, he was paying more attention to the trash, trying to discern some sort of pattern - if there was one.

Unfortunately, being a Cybertronian makes one hard to miss, even one as small as Bee. At least he couldn't be accused of directly staring - no pupils.