Would I appear jealous/overprotective if..?

[Cameron]

I reply to a comment made by some instagram follower of my girlfriend who always hits on her on every post she makes. He has even found her on twitter and tumblr. I have never brought it up to my girlfriend, but she has told me that she always gets a bunch of weird guys commenting on her stuff, this guy I just happened to see the most. We haven't been together long enough for there to be many pictures of us looking like a couple, other then one pic I took the other day. I was thinking of commenting a period in reply to his comment just so the guy could see the picture of us together on my profile. Would that make me appear like a jealous boyfriend?