What’s the deal with this fold?

What is causing this weird fabric fold on the trousers? I thought maybe the waist was a little big and the belt was causing it to wrinkle. But looking at the waist it seems ok (pics of the waistband attached). I did steam them thoroughly before wearing. Do they need pressing, is the thigh too big, something else?

Thanks in advance!
IMG_8059.jpg
IMG_8081.jpg
IMG_8082.jpg
Was this page helpful?