Skirts "riding up"

[BerryBlast]

Does anyone have any idea why my denim skirt (which isn't too small, honestly) keeps riding up at the front and what I can do about it?

I usually wear it with opaque tights, could this be the problem?
Any ideas gratefully received as I've stopped wearing the thing and I really want to wear it < wails> thanks

Old-fashioned, but try wearing a slip underneath.

Thanks Braaa, I do happen to have one tucked away at the back of a drawer - from the 80's (I'm a bit of a hoarder ) I'll give that a go.