So what if your mum or whoever else thinks you are mad/trying to be "posh" (whatever that means?)? You enjoy it and clearly are happy to spend money on it...is that not enough?
I understand the point about trying to help GA by dispelling stereotypes but in reality I think those who have a negative or uncomprehending reaction to light aircraft are never going to have much bearing on what happens to GA; I mean those who live near busy airfields will find it annoying...those who don't (the vast majority of people) will neither really know or care.
The word 'rich' itself is rather unhelpful in this case since it is a relative term and although a light twin owner like yourself is likely to be better off than the average guy in the UK if whoever you are talking to can't understand the difference between a owning a Learjet and an Aero Commander then they are probably not worth talking to. But even if you did own a Learjet and were worried/annoyed about what people thought....who cares....
Just tell them you worked really hard and now are reaping the benefits...
Edit to add: So are you going to fly yourself in the end to Budapest?
