Abigail has a job she enjoys and a husband she loves above all else.  He's her lover and her best friend, so when her fortieth birthday comes around she wants to celebrate in a way that both she and her husband will always remember.  Abigail's intimate party for three soon becomes four when she and her husband come up with similar ideas for celebrating her milestone.

I had a very difficult time getting into The Big 4 Oh.  The story was unable to grab my attention and keep me interested.  After starting it and stopping a few times, I was able to finally get into it and complete it.  Even though there were some positives that I did like about this story, such as the relationship between Abigail and Dave, the story as a whole just wasn't my cup of tea.  I didn't feel the story flowed very easily and I was rather confused by the need to bring others into their sex life.  I think I would have enjoyed this a bit more if it were a multiple partners’ relationship and not a multiple partners one-night-stand.  Although The Big 4 Oh wasn't to my liking, I'm sure other readers may find the eroticism and other factors of the story to theirs.