I'm having ex problems what should I do?

I dated this person about 6 months ago. An he just texted me sayin Ily an I know that means I love you. Am we never said the ilys even when we were Datin. I don't know what to reply back. An he also may be tryin to mess with me. Because he said he's at his friends an this friend of his is always messin with me an he knows I can't stand it. I just don't know what to text my ex bak. Do amy of y'all have any syggestions. Please help.