At first quick glace I mistook her for a man... this isn't the first time...
If it's true, well, let's see how long this lasts.
I'm thinking, if you end up in a relationship naturally it will usually last, but since his history shows he'd think of multiple women and just wanted to get into a relationship to prove something I think things will now slowly dissolve now that he has his "trophy".
That's a best guess anyway.
You know how people go on diets to loose weight and how once they reach their goal they drop the diet and then eventually end up right back where they started with their weight because they dropped the diet? My prediction is like that.