Hello Ineedhe1p, welcome to Psych Central.

Do you know that he is lying for sure?

A lot of people that are being abused find it hard to say and then panic because they are scared that they have just let something out that they shouldn't have. I mean, if he is being abused by his parents, he is going to feel very vulnerable. I would be inclined not to judge but to keep urging him to seek help. It can take a long time for someone to actually seek help and take that massive leap to tell someone about it. Be as supportive as you can, try not to question if he is lying because even if he was, there is an issue there somewhere.