My alleged boyfriend turns out to be a divorcee and he asks for online

I met a guy online on a dating website who lives in my own city. He has a business across countries and we both are working professionals. We met two times at a public place for some time and he except a handshake neither did we talk vulgar, just healthy conversation but he wasn't sure he wanted serious so we stopped talking. 2 months later we started chatting and our relationship began, he is abroad since a month so we were going long distance. Now during courtship he asked for sexy pics which i denied but after a lot of tantrums and emotional talks i gave him a little sexy pic. Then we continued and a few time we exchanged nude pics. Before this happened he had already proposed me and also said when he comes back from abroad he will talk to my parents and marry. Now I found out he is already married and they r separated but why did he hide it from me? Is he just getting pics from woman? Can I file a case? Did he just fool me by proposing and asking pics was he just going to use me?