Don't be surprised ,just remove him from your buddy list at once.We always meet the good guys and the bad guys,it is life,right?
On italki, someone said that: let's exchange! Join me in what's app ,Skype or wechat. I joined them, then they always asked: how old are you? Can you send me your picture? I see! they just want to find some beautiful girls or boys! They don't really want to learn to my language.If you don't want to learn to my language, pls don't reply me or join me, thanks.
"cheat on" is nor appropriate here. Use "cheat" instead.