FWB dating is the practice of keeping a friends-with-benefits arrangement going over time, as distinct from simply finding someone. It sits between friendship and a relationship, and it works only when both people treat it as its own thing and not as a stepping stone to something else.
Most successful arrangements involve occasional meetups without the routine of a couple. You might see each other every week or every few weeks. You share some time and some conversation, you are friendly in between, but you do not make plans together around birthdays, holidays or family events.
The important part is consistency in how you treat each other. If one of you is warm and attentive and the other is distant, someone will eventually feel used.
First, be honest about what you want from the beginning. Second, be exclusive about health: agree on testing and protection. Third, tell each other if you see other people. Fourth, check in every so often about whether it is still working. Fifth, agree how to end it kindly.
These rules are unglamorous, but they are the difference between an arrangement that lasts and one that ends badly.
End it if one of you has developed feelings the other does not share, if it is hurting your other friendships, or if it has stopped being fun. A short, kind message is better than slowly going quiet.
There is no standard length. Some last a few weeks and some a few years. What matters is that both people are still getting what they wanted.
Yes, if you both agree. Be open about it and keep to your health agreements.
Sometimes, but it is the exception. Do not take an arrangement on if the real hope is that it will become something more.