Not meaning to brag, but my girl and I (12 years strong) discovered 6 years ago that both of us were really into it, specifically her being bred.
We had our first experience together at that time, but then the topic disappeared again :-/ I was too shy to bring it up again and I guess she was too, but more understandably for her as she was the one doing the actual deed.
Well! Skip forward to early this year, it came up again! We were drunk or something, and we had gotten a German Shepherd 4-5 years ago AFTER we tried it.
Long story short: our shepherd is a frequent participater now
He's really damn big too, might I add.