According to well-placed palace sources, Camilla became enraged that Princess Mary was in attendance.
"She's long been jealous of the Danish princess and the friendship Mary has with Charles and she didn't hold back on her thoughts during the night either," a palace insider dished to New Idea.
The insider added that the whole evening was an "absolute nightmare - you could cut the tension with a knife."
Despite Camilla's drama, the Queen spoke fondly of her son and his wife during her address on the night.
“It is a privilege for any mother to be able to propose a toast to her son on his 70th birthday. It means that you have lived long enough to see your child grow up. It is rather like —to use an analogy I am certain will find favour — planting a tree and being able to watch it grow,” the Queen stated in her speech on the night.
“My mother saw me turn 70, of course. And she was heard to observe that 70 is exactly the age when the number of candles on your cake finally exceeds the amount of breath you have to blow them out,” she continued.
“Over his 70 years, Philip and I have seen Charles become a champion of conservation and the arts, a great charitable leader — a dedicated and respected heir to the throne to stand comparison with any in history — and a wonderful father.
“Most of all, sustained by his wife Camilla, he is his own man, passionate and creative.
“So this toast is to wish a happy birthday to my son, in every respect a duchy original. To you Charles. To the Prince of Wales.”