I think we're actually the same person! Except I choose Emily over Anne.
That is so sad, and I'm so sorry that happened to you. You should ask these people why; it's a terrible thing they did, and you do deserve to know why they all abandoned you like that.
Oh! You are exactly who I thought I would be when I was young. Your life sounds so fulfilling. Enjoy it to it's utmost and don't let anyone tell you how to live it.
Really, what does it matter if they did? Presumably Kourtney is aware of it and doesn't care. It's not like they're being accused of having an affair now.