Wrong Shop?

Last weekend I went clothes shopping with a friend in Dublin. He found a shirt he liked but all the trousers were wrong in some way so we went and had coffee instead.

On the way home I commented:

I don't understand why none of those trousers fit you right because you wear M&S trousers all the time.

He studied me a moment perplexed.

We were in Dunnes not M&S.

Ah.

Puzzle solved so!