In SL, I do not really worry about who the RL person is, I try to take them for who they present, just as I want to be. When I want RL, I log off. Back before SL, though, I had a number of on-line relationships where I was presenting exactly who I am and they supposedly were as well, and like you it was important to me that they were. The way I handled it was to invent a character in my head. His name was Denis and he was 53 year-old postman in Dunstable, England who lives with his mum and is completely unremarkable in any way except one: he has a remarkable talent for pretending he is a woman on-line. So every time I started chatting with someone, I would start with the assumption that "she" was Denis until she convinced me otherwise. You know. Not right away, but if you are cleaver, you eventually know. It just takes a few weeks or months. There is a smell to truth if you are looking for it. Truth is weird and full and messy and not the way you want it, but it still adds up. Lies are clean, tidy, and too good to be true, and yet little things just do not add up. Listen to your gut, but you need to tell your gut to actively listen. And real women simply interact differently than Denis thinks they do. Denis actually is usually not as smart as he thinks he is so he ends up getting careless.