The woman explained she thought it would be helpful to hear examples from other women so she knew she wasn't alone.
Dozens of people responded within just a few hours, dishing the dirt on the very worst things their mother-in-law had ever said.
Weddings and grandchildren proved a common trigger point for many.
One woman shared: 'When we told mil [mother-in-law] I was pregnant (planned) and she said "oh well accidents happen".
'And when dh [darling husband] went out the room proceeded to tell my how much his ex had wanted his babies and they would have been a lovely family!'
Another shared: 'When we asked her for baby name suggestions, [mother-in-law started out with DHs [darling husband's] ex's name.
'He's had just the one LtR [long-term relationships] before me (apart from a couple of relationships that lasted a month or so) so it wasn't that anyone forgot, and unusual name too.'
A third added: 'MIL [mother-in-law] told me in the run up to our wedding "nobody will be looking at you anyway" when she discovered a friend of mine from Uni who is now a make-up artists was doing everyone's makeup for the day.'
Others said their in-laws did little to hide their disapproval, resulting to outright insults.
One posted: '[My mother-in-law] regularly made snide comments, not at all subtle, e.g. when staying with us saying "Isn't she spoilt? Look at our poor son doing all the cooking! She's so spoilt isn't she?" All to [my father-in-law] while I was in the room.'
