Passersby saw the man clinging to the second-floor balcony railing of an apartment in Barletta, Puglia, and then falling.
They thought he was a burglar but it later transpired that he had hidden on the balcony after hearing his lover's husband return home.
“He hung to the railing so as not to be seen,” a police officer in Barletta told The Local.
“He was there only a few minutes before falling. The wife called the emergency line.”
The officer added that the railing was unable to hold the man's weight, and so he fell.
He suffered spinal fractures and other injuries and is recovering in Barletta's Dimiccoli hospital.