I remember an interesting bit of gossip I heard, when I was at W magazine: Donatella's husband at the time, Paul Beck - a gorgeous former male model - was actually Gianni's lover.
For years, Gianni wanted a child and heir. He and Paul couldn't make *that* happen. So, he brokered the marriage between his sister and lover, which produced Allegra and her brother - can't think of his name...and viola! Instant heirs.
Whenever they came into the office, it was always the happy threesome...Donatella coked out of her mind, in a leopard catsuit unzipped to her navel, gold stilettos, white'ish blonde hair and Vuitton bag tan - Paul in distressed button-fly jeans, and a plaid flanel shirt with the sleeves artfully ripped off - and Gianni, smiling, impeccably well put together and warm. Wow...that was a long time ago - but, good memories!
To be taken with a grain of salt, but it still kind of makes sense...