How we change what others think, feel, believe and do
Innuendo is 'saying something without saying it', often implying something negative or politically incorrect, through allusion or insinuation.
She's got a great future in front of her!
Is that a gun in your pocket or are you just pleased to see me?
Know what I mean? Nudge, nudge! Wink, wink!
When you are prevented from saying something due to social norms, such as when certain words are forbidden or even from politeness, then it is common to try and get others to understand by using metaphor of some kind.
If the person using innuendo does not get the response they require, it is not uncommon for them to increase their attempts, exaggerating the innuendo or using further suggestion.
An advantage that innuendo gives the person using it is that it deniable, should they be called out for making improper suggestions.
Sexual innuendo is common, particularly in drama that written in times when explicit language could not be used. Used well, it can create a humorous situation, for example by referencing sexually-related parts of the body.
Innuendo can also be produced without language, using gestures and substitute items such as melons.
Sexual innuendo is also used in flirting and may be unwelcome.