Helen has forgotten her 20th wedding anniversary and, when she's reminded of it, she hastily throws a party where all kinds of revelations come out such as

Neighbour Jeremy who is married to the local GP Harriet is in love with Helen, Helen's youngest brother Marcus who is married to Imelda who wants to get try experiment with different things in bed, Helen's older bother John is engaged to Debbie, who wishes he was a bit more well endowed, and Helen's son Tim is having too much sex with the wrong people but Helen and Tony think they have a solid marriage until a former ex pupil shares the biggest secret of the night.