There’s no way regular man-sized pants would stay on after the Hulk goes all hulk or whatever!
One of the biggest mysteries in all the comic book universes is what the hell the Hulk’s penis looks like.
g val, it is meant to be Betty. The point of the gag is that whilst Betsy Ross made the flag, Bruce’s girlfriend in the Hulk comics is called Betty Ross. I did have to look that up – I’ve learned something today