To me...this is no different than two people getting engaged who have decided they never want to have kids...and then one day, one of the people says "I want kids"

In Rob's mind, the relationship was built around a single idea...strict monogamy. When he found out his fiance was interested in fucking other dudes...he found himself no longer interested in being with her.

Now you can say...everyone wants to fuck other people. Which is true. But not everyone throws caution to the wind and says they want a MMF threesome without first gauging their partners willingness or openness to the idea. Rob thought he was marrying one person, and as it turns out, he was marrying someone different. He thought he was marrying a strictly monogamous woman, and instead, he found out she has a strong desire to fuck other dudes and maybe try an open relationship.

Rob, like other people who know 100% they are strictly monogamous people...are allowed to say that the strong desire to fuck other people is a dealbreaker. The fiance knew there was a chance this could cost her her relationship....and because the desire to fuck other people was so strong...she threw caution to the wind and said this is something she wants.

And in the end...it did end up costing her her relationship. And in the future, she will most likely only date men who are open to the idea of fucking other people.

Sometimes...people are just incompatible