Widow who has had more than 100 affairs reveals why Valentine's Day is the best time to be a mistress

"In my experience, the gift to the mistress tends to cost double whatever they give to the wife, and it is far sexier," Lee said. "I've been a wife on Valentine's Day, when I was married to my late oil executive husband, and all I can say is that being a mistress is a lot more fun."

"The sad truth is that monogamy is unnatural. Who decided that it was good idea to commit to one person in your 20s or 30s and then stay with them for the next 50 years?" she said. "Where is the fun in that? Inevitably the sex is going to go stale."

"Go out on Valentine's night and you will see thousands of couples staring at each other vacantly over dinner. 

"They have very little in common, sex has become a routine and they have stayed together for the sake of the kids or because it is too expensive to divorce."