Challenging Me?

On Saturday, my mum suddenly ask me to come out and play guitar with my sis hubby. The thing is my mum thinks I cannot play guitar at all. It is just that I REFUSE to play for their CG coz its like not my CG and they always sing off tune. So thats when my mum told me to play with them and I strut my stuff NON STOP. My sis hubby kept on telling me to have a few songs in the head which in my head, I have damm many songs and I can play non stop. After a while I just walk off as I knew no point to continue coz I know what I can do is more than enough even though I am not professional.