I hate it when, so called, fashion experts make blanket statements like, "curvy girls shouldn't wear skinny jeans" or "never ever cuff your jeans". Who are they to tell you what to do? They act as though their fashion preferences should rule your life. Those same "experts" are now describing the best way to cuff your boyfriend jeans.
1. Beat the cuffs into submission by ironing them flat.
2. Use double sided tape to create a real sticky situation.
3. Sew the cuffs in place at the side seams of your jeans if you don't mind a more permanent solution.
Caution: All three of these tips can cause a permanent crease and slight discoloration to form at the cuff site.