Someone or something that makes you happy on a daily basis. Just having that person/thing in your life makes you happy. You think about this person/thing so much that you have to try and stop yourself to be able to focus on other things that require attention in your life. This person/thing is amazing, beautiful and knows how to bring a smile to your face on the darkest of days.
When someone has literal or figurative control of a man through a grip on his testicles (getting his conpliance by squeezing or threatening to squeeze them.
Mike was doing dishes because Ann had him by the balls (literal)
Big business has the world by the balls (figurative)