This is a talk that should have been done before you got too serious, to help prevent anyone getting hurt if one doesn't agree.

Kick her ass to the curb there's not point in getting married if she just wants to sleep around you don't deserve that.

Can't turn a hoe into a housewife :-(

Open marriages do have their benefits. While some couples get bored with each other, cheat, then divorce (by that time, children are usually added to the mix,) couples in open marriages are free to have some side fun while still remaining committed to their family.

She is a smart lady: try eating only black caviar and champagne for the rest of yoyr life. Evere day. Three times a day. Then tell me in a year that you still enjoy it and never even consider anything else.

I think it's time to drop her OP

Run, Bro.

I think the best thing you can do is sit down with her and have a long and honest talk about where you both see this relationship going in the long term. Clearly you are both on the same page about getting married. But the boundaries of that marriage need to be negotiated and clarified before that beautiful day. I know a couple of people who are in poly-foursomes or moresomes and a married couple with an open relationship. Their relationship dynamics are weird as shit to me, but I'm pretty sure none of them cheated before the rules were worked out between them. Just because they're different doesn't make them any less committed to their primary partners. Nor does it make them 'bitches' or 'hos' or 'floozies'. That's just being judgemental of a lifestyle that people clearly don't understand. I don't pretend to understand it either but us deviants have a saying: Your kink is not my kink but your kink is ok.

She just gave you the fancy b.s. runaround that translates into: I fear commitment and I really just want to have a lot of sex with everyone except for you.

Run.