Wife/Husband Swap?! *Update*

My husband and I have been together for 8 years and completely in love and faithful to one another. Throughout the years we have briefly discussed threesomes and foursomes but agreed it wasn't for us. Last week my husband became increasingly more interested in the idea of swinging with our best friends who are also a married couple. They are open to it and so is my husband. I'm the only one that isn't sure. I was curious if anyone here has had a similar experience with swinging good or bad. I would love to hear about it!

*Update*

Thank you everyone for sharing your thoughts and experiences. Although I am a very secure and open minded person I do agree that this is something very personal and not for me. I fully respect people who are able to do this, live that lifestyle and have open relationships but it's not for me. I've had long conversations with my husband and he realizes how deeply hurt I am by this. I'm taking it day by day at this point and will work on getting past this. Our friends are also very understanding and agree if not everyone is 100% it shouldn't be done.