[Black winter day]

Wasn't sure where to put it, but i know a lot of guys here play HU, so:

Are there any non-written rules?
I've been berated and hitnrun so many times that i basically do whatever i want and do not feel obligated to anyone - if i feel like quitting after stacking someone, i will.If i feel like quitting after 15 hands when i see that i am neutral EV vs villain, i will.

I don't expect anyone to stay after busting me and those "gg, gtg" after taking 2 BI off you makes me feel even worse.

I am fairly new to HU so i am not really how things work for the rest of you, do you uphold any rules?
When do you quit a guy?