No, it's not fair to him. But it's also not fair to him or anyone else for me to not be "real".
Real right now is that I'm in no position to uphold the responsibilities of being a girlfriend.
Our relationship is based on the reality that we're committed to each other for life-regardless of what DYNAMIC we have.
So, to quote GG, "the dynamic has changed, that's all".
It's changed many times, it may change many more.
"Love As Thou Wilt"