The three-year-old's mum was left red-faced when the neighbour popped around the return the raunchy love letters.
The husband, who wishes to remain anonymous, told Mirror Online he's received from funny looks since the embarrassing incident.
"My daughter found them and went on her Postman Pat delivery.
"A neighbour returned some of them to my wife. Oh happy days.
"I think the neighbours read them because when I arrived home I got some funny looks."
It's not the first time a family has been left blushing over old love letters.
Just weeks ago a group of sisters who thought they uncovered their parents' romantic correspondence were left horrified after reading what was inside.
While their father was working away in London in the 1960s, he sent letters to his wife back in Scotland to reassure their love for one another.
Those love letters were stored away for more than 50 years, until the couple's daughters stumbled across them.
Read more: • Kiwi parents reveal the hilarious ways they deliberately embarrass their kids
Twitter user Morven from Scotland explained how she and her sisters decided to sit down and read the letters together as a way of remembering their mum.
Unfortunately, they weren't prepared for what was inside.
"After my Mum died we found letters, tied in a bow from my Dad from when he worked away in London in the 60s," she tweeted.
"My crying sisters and I held hands, opened one and the whole thing was about how much he missed shagging her, apparently a bit of a goer. Didn't read the rest."
Read more: • Clarke Gayford's parenting tips