How would anda define a good sexual relationship?

It's pretty simple in my opinion. Call me naive but that's how I see it.

1: knowing your partner very well, to know what gets her engine running. This can only be achieved with a deep emotional connection.
2: Her pleasure before mine and vice versa
3: It's a two way street, both parties have to put effort into it.
4: A certain amount of kinkiness never hurts. ;)