If you slept with a guy on your first date you tell him not to mention this to anyone he tells you this is not going to be a one night stand and he calls you the next day is this a good sign?

I think it soulds pretty good so far. I have dated a lot in my life and when a guy isn't interested in more than a one night stand, they stay away from that topic entirely. The fact that he was willing to talk about it and even called you the next day, seem very positive to me.