Colin really was not, Zach judged, used to much human touch, at least of...well something. But most people didn't blush when holding hands. Most people also knew what sex was and didn't need a why for having it. So Colin was quite peculiar, and it was cute. Zach was content to watch it. And here it had at least something to do with him, with holding hands that was.
And there were things like that - the fact that Zach had been complimenting Colin's looks, not his manners or person. He deserved compliments for those too, but Zach had intended it to mean otherwise, and Colin completely missed it. "We could meet up in places where you aren't staying," Zach suggested, "So that I don't know where you are. And we can communicate via the journals." Zach worried his lip after saying that. They weren't necessarily the safest.
"I still have my galleon from the DA," Zach added, "but that would communicate with a lot more people. Currently." Protean charm. Sure it was possible to charm something else too, but that would require Colin to carry around even more stuff while on the run. But maybe he could modify Hermione's work somehow?