The 50-year-old music mogul proposed to make-up artist Mezhgan Hussainy on Valentine`s Day in February, and the pair were planning to wed later this year. However, Simon could now postpone the ceremony until next year because his schedule is full.
The star is launching a US version of his hit TV talent show The X Factor, as well as being head judge in the original UK series of the programme in the next six months. He is believed to be concerned he would have to rush the nuptials and honeymoon.
Mezhgan, 36, is reportedly worried Simon`s decision to delay their wedding is a sign he is having "cold feet". Before meeting Mezhgan, the star had vowed to remain a bachelor forever and the brunette beauty fears he is having second thoughts about their romance.
"She will ask him outright if he is stalling the wedding plans because he has got cold feet," an insider told British magazine Star. "Mezghan is nervous and edgy about the whole thing, but she wants some straight answers so that she doesn`t end up looking stupid.
"She is madly in love with Simon and worships the ground he walks on. But he has to convince her he feels the same."