Whilst watching a movie:
Alpha: That reminds me of this one time....
Alpha's Girl: Tell me about it!
Alpha: [Tells long story that makes him look good.]
Alpha's Girl: Ooh, you're so awful! [Has sex with him.]
Sigma: That reminds me of this one time....
Sigma's Girl: You've got to be kidding.
Sigma: It was actually worse, because -
Sigma's Girl: Stop! Stop now! I don't want to know! [Has sex with him, sleeps with one eye open.]
Women are as strongly drawn to the Sigma as to the Alpha. But instead of having to deal with the simple angst that stems from unfaithfulness, they tend to find themselves facing a wide range of much more complicated angst. A quality Alpha story leaves the audience in a celebratory mood and inclined to exchange high-fives with the Alpha. A quality Sigma story leaves the audience amused and slightly alarmed.
And remember, a woman's hamster loves nothing so much as a vaguely sordid and possibly dangerous mystery.