Awkard relationship

Express interest in what he is interested in and keep up the conversation. Is this someone you could potentially meet (e. g. is he local)? If so, then suggest getting together after you've been chatting for a while (say, a month). If he's not local, then maybe suggest facetime or skype or the like, again, after a while of chatting. Good luck!

Tell him to cut out the provocative flirting. It's not needed for your interest.

(But I would be wary of someone who sends these kinds of pictures.Geez - you don't even know him and he does THIS?)