Around 4:30 am on Sunday, she was woken by the sound of what she believed was her son Stewart Kinsey drunkenly returning home from a costume party.
She found the inebriated man, whose face was painted to look like a skull, lying on her dressing room floor under a duvet cover.
Jarvis slipped a pillow under his head and adjusted the bedding to make him more comfortable, like any caring parent would, before returning to bed.
Hours later, Jarvis’ husband delivered some unexpected news, telling the 49-year-old, "There's a naked bloke upstairs, and it's not Stewart."
The 29-year-old had been kicked out of a club in nearby Surrey after falling asleep, and somehow made his way to Jarvis’ home -- quite a feat, considering it was "in the middle of nowhere" and more than 3.5 miles away from his house.
Sharing the hilarious encounter on Facebook, Jarvis admits there were a couple of signs the man she was lovingly tucking in wasn’t, in fact, her 30-year-old son.
"When I gave him a pillow he said ‘thank you’ and I thought, ‘Hmmm, Stewart sounds very polite," she wrote.
She was also surprised that her son’s car wasn’t outside and that he had decided to drop in for a quick nap at such an odd hour.
"But he looked like my son enough to pass a cursory. (Stew changes his hair and [facial hair] a lot)," she continued. "I thought his hand looked mucky, but figured it could be that his car broke, and just thought, ‘Ah well, Stewart does funny stuff, he can explain what he is up to in the morning’."
"[He was] obviously housetrained by someone, he knew not to walk mud through, his shoes were in the conservatory [an enclosed porch]," she added on Facebook.
Campfield admitted had no idea how he ended up in a stranger’s house and tried to pretend he was a friend of Stewart’s when he was discovered.
Alas, it didn’t work.
"The lady took a picture of me to send to him — I knew then I had been rumbled," he tells The Sun.
As for Stewart, he’s not overly happy with his mother.
"I’m going to have some serious words with my mother — she still can't recognize me after all these years," he joked to The Sun.