Despite the fact that the couple have been dating for five years and even own a house together, the woman admitted she was worried she was being led on, so decided to confront her partner about why he hadn't popped the question.
But his response left her completely shocked and has sent users of the online forum into a fury.
In her since-deleted post on someecards, the user revealed her partner won't propose until she loses weight.
Explaining that her weight is something that she's struggled with since her teens, the woman admitted she wasn't upset by his response, adding that she wants to change her appearance.
'What I am upset about is that he is using being fit as a condition of marriage,' she added. 'That if I stay the same, we will simply continue dating.'
'He says that he wants to spend his life with me and that he isn't going to break up with me but he really wants to see me more fit.'
Users have since jumped to the anonymous woman's defence, insisting that she finds someone who will love her simply as she is.
'Find someone who'll love you in sickness and in health, not if you change your body for them,' wrote Littlestray.