Get out. Now.

actually the worst fml I've seen today, my condolences

well sex equate to pregnancey and that equates to parenthood stupid womman.... OP..just RUN !

At least she brought this up before the marriage happened. In my opinion, she's helping you dodge a bullet!

I really feel like she said this for fear she'll get bored being in a monogamous relationship in the future. If she has been with only you all the time she's dating, then she is capable of being with only one person. She does plan to marry you in the future so she may love you but be afraid that five or ten years down the road she'll be unhappy sexually. At least that's my take

Marry her!! What is good for the goose is good for the gander!

if that's the way she wants to be when your actually married, I'm sure she's probably already started being pretty... "open." beforehand.

Can't stay monogamous? Time to get married! I think your girlfriend is getting married for the wedding and not for your relationship. Obviously you two have different views on a very important part of your relationship (da sexs, bro). Normally I'm not one for "Oh, leave her!" but OP, I really don't think it would be a good idea to stay with someone like that. If she can't understand why you're upset about her remark, than she'll see nothing wrong with her actions. (You're over-reacting/being a drama queen). Good luck OP in whatever you decide.

Why is she your fiance?

she just basically told you she's going to cheat on you. unless you're okay with years and years of her sleeping with other men I say get out, and get out fast!

Why are you complaining? You just got a perpetual hall pass.

While the concept of an open-marriage isn't a terrible one, the fact that she waited so long into the relationship to mention this kind of makes her a b-word.