my ex-boyfriend is talking about suicide.

this is what he said in a g-chat:

"the other day I was really sad and I was telling a friend that the only reason i dont kill myself is to see how ****ed up everything gets.
so technically i am more curious than depressed"

he doesn't know I'm married (he still wants to be together). we live in different states now. I don't know what to do/say. he has been talking like this for months now but not so explicitly...I am the only person he is really close to. My dad is visiting him today but then he'll be alone again.