The couple is said to have met in 1710. The Duchesse's passion for him grew so fervent - as illustrated by the intense letters they exchanged - that she suggested that they ran away to Holland. However, La Haye was well-aware that his mistress was far above his own standing and her father - the Duc d'Orléans - stood to become Regent. To put it simply, La Haye was afraid of what would happen if he complied.
He refused and had to endure the tantrums she threw as a consequence. Changing between fits of tears and overtures of love she tried to sway his mind but to no avail.
|The beautiful Duchesse de Berri|
Instead, he went to the Duc d'Orléans and reported the Duchesse's proposal. Understandably, the Duc d'Orléans was not pleased but was also too fond of his daughter to severely punish her. He made it clear that her scheme was never going to materialise; then he turned his attention to keeping the scandal far from the King's ear.
It was not possible to keep it from her husband, though. The Duc de Berri was more than frustrated by his wife's countless infidelities and saw the choice of her new lover as another insult. He threatened to have her sent to a convent but never followed through - it would probably have been difficult considering that her father was soon to become Regent.
Exactly how many knew of the affair seem to be unknown. Saint-Simon reports that "everybody knew" since the lingering looks cast between the two at Marly left no one in doubt. Although, the affair inevitably cooled down after the revelation of the Duchesse's wild scheme it was not quite over. At least the Duchesse was said to have loved La Haye for a while after her husband's death. After that event she secured him a new employment since he could no longer be an equerry.