I don't think the best or most mature answer to his attitude is "I open a profile too and post nude photos to make him jealous" but this is just my advice, i don't know your relathionship. Try to talk, not just start a "web war".
And most of all, if he likes getting public attentions from other girls while he's still with you, maybe, just maybe, he's an asshole, and I say this with all due respect to you
And most of all, if he likes getting public attentions from other girls while he's still with you, maybe, just maybe, he's an asshole, and I say this with all due respect to you