Think of:
* A timid, easily-bullied husband who is constantly deferring to his wife.
* A meek, nervous character who is afraid to assert himself.
* A character who is overly eager to please and will do anything to avoid conflict.
The "whimpy" voice emphasizes the character's lack of confidence and assertiveness.
It's important to remember that this is a general stereotype, and there are many different ways to portray male characters in media.