Karen is a single mother of a teenage boy, and controlling of his life so far. She is resentful of his father and refuses to take Alex to his dad's wedding. But when they prepare to take Juliette off to the old people's home, Karen's son Alex becomes inspired by his free-spirited grandmother and begins to stand up for himself.
Alex is gobsmacked to discover that his grandma's fantasy boyfriend is in fact real - and there is a showdown where Karen reveals she has already warned this man ,who is about her own age, from visiting her mother Juliette who has early stage dementia. To Karen, this is sexual abuse.
Alex is moved by the words of his grandma's lover Ronan, realising that this relationship is one based on love and romance. Something his mother has clearly little experience of.
Alex helps his grandma elope with Ronan, and also drops a bombshell with his mother that he has been accepted into a university that is miles away from home - and near his father's house.
Juliette is returned by the police and she is about to be taken off to the old people's home. But when Alex reveals he will be staying at his father's house whilst attending university miles away from Karen, she let's rip on the plant pots that her mother has been buying in bulk, and finally expresses the emotions that she has been holding in for a lifetime.
In a final scene between Karen and Alex, Karen offers to drive her son to his father's wedding. As Juliette appears, another idea occurs to her - a final twist in which Karen not only shows she has lost some of her resentment of the father of her son, she also makes us laugh as we see she still, in her own way, has the upper hand.