You can't convict someone of a crime that he has not commited. He might have said he'd sneak out to meet her but people say a lot of things using the anonimity of chat and if that kinda thing stands in court, then that in itself would be illegal. People make threats about killing others all the time, if you arrest everyone of them I think that would be stupid. I'm not sure what kind of picture he forwarded but as long as that photo is not indecent, I don't thing the law officers have much grounds to prosecute him.