Slightly different, but when one of my sons visits with his wife and 2 boys, now aged just 18 and nearly 15, for several years now son and his wife have stood up whilst the boys have sat down (we don`t have a lot of spare seating). I`ve regularly said to them "a gentleman would get up and let a lady sit down", to no avail, and their mum always says it`s OK, she doesn`t mind standing.