<human>: Summarize the given text in a few sentences.

He's been cutting himself lately whenever we get into a fight or when he's super stressed. I always want to help him, be there for him and stuff like that but every time he does it and I ask him what happened he'll make up a lie, that's very convincible. So I believe him and then when we get into a fight he'll just randomly out burst and say that cut on his face, neck or arm is from him scratching himself, it looks bad, so ya in a way he cuts himself just not with a razor. I talked about it with him and I said it hurts me when he does it but it hurts even more when he lies about it, so on and so on. Seems like he's telling me now but problem is I wanna help him try not to do it.
<bot>: He now tells me that he's cutting himself from stress and fights we have. The problem now is, I really want to help him to stop doing that but I don't know how to. Any advice?