My personal sexual fantasy is a twin threesome or being in bed with two contrasting women who are physically and verbally fighting for my attention, so kind of.
You know how in a lot of YA novels, the female protagonist has two hot dudes who are opposed to one another in terms of personality competing for her affections? That's the appeal.
It illustrates that you're desirable as an individual, provides two different personalities and reactions to your love, and the fact that there are two of them means that the likelihood that both of them fell in love with you over a fluke is astronomically low, especially because they're actively fighting to have you to themselves. Plus it absolves part of the guilt of 'cheating' on them because they're implicitly accepting the threesome as a way to prove their superiority to the other woman.
On a primal level, two different women means greater likelihood of having children, and greater likelihood that at least one of your children will be successful.Deep down, I just want to be loved.