Redherring underpants: so comfortable you'd hardly know they were there. And, measured by one important yardstick, they often aren't.
Not necessarily a design flaw, merely a use case the designer failed to consider. The button is oddly placed for a man of my, er… stature, the main consequence of which is that throughout the day I occasionally flop out. Not protrude or stick out, no. Flop.
It's not a pleasant feeling, but it's not entirely unpleasant either, knowing that a change in posture will precipitate a contact with one's outer garment. The very worst situation (if I'm being honest 'worst' is exaggeration) occurs when I'm neither in nor out.
Enough words, I just got changed into my dressing gown, it's more predictable even when moving the bins to the front of the house on collection day in high winds!