Was it a mistake?

A little over a month ago I went out drinking with one of my lady friends.. she was just a little bit too drunk to drive home so she stayed with my fiance and I. Welllll... her, my fiance and myself were laying on my bed and she said "I want to watch you suck his dick." Sooo.. I did.. next thing I know me and her were kissing each other, she was sucking my fiances dick, I was eating her out, he played with and sucked both of our nipples, we both licked my fiances dick and ended up me having sex with him and me and her tribbing... I really enjoyed it.. (I had a girlfriend before, so this is nothing new to me) however fast forward a few weeks later and my fiance is asking when we can do it again.. I would love to.. but would it be odd??