The guy doesn’t sound sketchy to me, in fact it sounds like he has given up on you because you’re so hesitant to meet him.  I’d be flirting with other women too if we weren’t in a monogamous relationship.

Try to imagine what it feels like to be a guy: he’s supposed to just drop all the other women he’s talking to because he is supposed to magically know that you’re expecting him to?    He hasn’t even met you and you’re already expecting monogamy?  He is supposed to not flirt with more than one woman at a time?  Why?  How could that possibly be a sane thing to do when you won’t even meet him in person?

Try to realize that just because you feel an emotion doesn’t mean it is justified.  Our brains are complex and emotions rise up in us for many reasons.