I don't know that I'd ever feel the need to formally "leave" the TMF. Deactivate my account or delete it or whatever. I would just stop coming around if I got bored with it, and start coming around again if and when I felt curious about how things were going here. I guess it all depends on why you come here. If you're coming here to meet a partner and you meet them, you may not need to come here anymore. If you come here to look at porn and you end up with a significant other who doesn't like it, you may stop then. If you just come here to chat and be social and keep up with friends, like I do, then unless you start to hate those friends, there will never be a reason to completely leave. At least not one that I can see.