Help!

Hubby keeps putting little girl's pants on little man and vice versa. He changes them both in the morning after I leave the house. Any suggestions for getting this to NOT happen? Little man is beginning to look like an elf in short pants and little lady looks like she is wearing parachute pants. PS - Little lady is one size smaller and usually wears little man's hand-me-downs for pants. I have no idea how to help hubby if he isn't going to look at the size of the pants!