How long has the nest been empty ?
Are they your natural/adoptive children ?
There is allot to the empty nest syndrome. I think you should seriously consider this. I can assure you, this is important.... Things change.
Having great sex doesn't fill the nest, its a temporary soulution at best.
Talk to her about the empty nest, someone should.
As far as her raising her ass while giving you a blowjob...... God I love that

Mrs fun does that just for me too
If Mrs fun is thinking of another man doing her from behind.... I wouldnt know, the rythmic movements of her ass, kind of puts me in a trance