<human>: Can you give me a shortened version of the text?

My SO[25M] and I[25F] have been together for four years, We are happy, have an already great sex life and share on odd sense of humour.

We had always talked about having a MFF three way as it has always been a fantasy of mine to fuck a woman and luckily for me a fantasy of his to watch me. 

The first time it happened was Halloween. I met her[20F] that night my SO had met her a few times previously through mutual friends. There was a large group of us all drunk and dressed up and having a great time.

from the get go she and I got along very well and it wasn't very long before she was all over me. The drinks were flowing so she admitted silly things to me like having always fancied my SO then when I walked in realising that he was punching above his weight and that I was incredibly beautiful. We very publicly got it on in the club and then all come back to mine and my SO flat. 

The sex was amazing, she is amazing and her body AMAZING. It was quite scary how comfortable we all were with each other the next day all just laying around naked stroking each other an talking about our lives.

It has happened twice since then every time involving us very publicly and openly taking her home after a party. The second time was all about me and her my SO didn't get a look in for almost two hours but we made up for that.

The third time I was so drunk I passed out almost as soon as we got home and do not know what happened between them and it makes me feel quite sick. My SO tells me they didn't fuck each other they just cuddled and fondled and I do believe him. 

So this is why I ask my question is there any way this can go on with out either me or him getting hurt or it becoming messy? at the moment my jealousy is under wraps which is mad because previously I have been an incredibly jealous person.

Just to add [20F] has a boyfriend of her own that lives away due to her being at university.
<bot>: My SO[25M] and I[25F] have had several MFF three ways with the same person[20F]. If this continues will it ruin our relationship?