There are some things people tend not to say to their closest friends.
Do you tell your friend that the dinner they cooked for you is terrible... or straighten your back and dig in?
And what about that friend with the dodgy jokes? Do you laugh politely or tell them the cold hard truth?
YouGov recently conducted a poll into off-the-table topics between friends - here are the most taboo truths.
Being a bad parent comes in at close second, with only 21 per cent willing to drop that particular truth.
The suitability of your friend's partner is also a topic left unsaid, and 76 per cent of people wouldn't venture into that territory.
The data implies that British people do not tend to criticise their close friends on topics that are personal – related to their family and character.
However topics such as politics and other 'hot' subjects are fair game – 78 per cent of people would tell their friends if they disagree on something they feel strongly about.
The poll also shows that men are more likely to be straight forward about the hard truths than women.
Twenty-two per cent more men than women would tell their friends that they have poor taste, and 17 per cent more that they are not funny.
In fact, the only truth more women would tell their friends than men, was if their partner was cheating on them.