Aunt Sue appears in Season 4. She Becky and Laura's aunt and Jill's sister. She has husband named Dennis and a daughter named Bianca who was a bridesmaid at Paul and Laura's wedding. In addition Sue was one of Paul and Laura's witnesses and also made their wedding cake.
We are first introduced to Sue in Episode 1 of Season 4: The Morning. Steve and Lee met Sue and Dennis in the lift whilst they are looking for Paul. As with all of Becky's family Sue and Dennis adore Lee, but treat Steve with cold indifference. This indifference rapidly turns to dislike and anger after Steve admits that he left Paul in the bar the night before and they later find him in the garden drunk, half dressed trying to kick over a large plant pot.
Sue's negative attitude towards Steve is cemented further by the content of his best man speech, Sue herself reprimanding Steve on it's "inappropriate" content.
Sue is played by Victoria Willing (most widely known as Jay's mother Mrs Cartwright on the Inbetweeners).
Victoria Willing was joined in Series 4 by 2 of her Inbetweeners Co-stars; Robin Weaver who plays the registrar at the wedding and Jonny Sweet who plays Paul's half brother.