That's even worse; she's done this before. Both her husbands probably believed her when she said "I do" to:

"[Wife’s name], do you take [Groom’s Name] to be your wedded husband to live together in marriage? Do you promise to love, comfort, honor and keep him for better or worse, for richer or poorer, in sickness and in health, and forsaking all others, be faithful only to him so long as you both shall live?"

She's not a faithful woman; she hasn't been faithful to the other men, why do you think she would be to you? It does not sound to me, that at 25, you have had very much experience with women or know yourself very well that you would allow yourself to get in this mess and be trying to make a silk purse out of it anyway.