This is actually really great advice! Thank you!
Go carefully with this one. You’ve never met this guy, and he’s a colleague. He may well be messaging loads of women from work in the same way, as a way of passing the time. He could be one of those guys at work that always goes after the new girl, who you would ordinarily be warned about by the other people you work with! I’d actually find it a bit creepy if someone started contacting me like this in this kind or scenario.....!
I’d try to just keep it professional, until you can at least meet him in person and start to really gauge what he’s actually like.