The reality TV couple, whose post-house documentary Josie and John James: What Happened Next? aired on Monday night, were photographed hugging and kissing each other goodbye as Parton prepared to return home to his native Australia.
"He has some business to attend to over there but he's mainly gone to see his mum," a spokesman told the Daily Mail.
"He went into the Big Brother house, came out and has been working ever since so he hasn't seen her recently. He'll probably be there for about ten days but he has an open ticket so he can pick and choose when he comes back."
Gibson, who won the final series of Big Brother on which the two first met, later took to Twitter and thanked fans for cheering her up following Parton's departure.
She wrote: "U guys make me laugh readin' some of ur tweets. Even tho I'm missin' John badly u lot always put a smile on my face x x x. (sic)"
Speculation that the couple are planning their engagement emerged this week, after they were spotted shopping for diamond rings.