It is referring to a males private place.
dude you got a nice dick in there use it on some girl
The phrase "passion in your pants" is a colloquial expression that typically refers to feeling strong sexual desire or arousal. It suggests a strong physical or emotional reaction to someone or something that excites you. It is a metaphorical way of describing intense feelings of attraction or passion.
flash in the pants
ants in youre pants
it means he peed in his pants or he wet his pants
Also, I have a passion for
Ma is feminine for my and passion is just like in English it means passion or what you like to do. So the whole thing means 'My passion'
Your britches are too difficult for your mind to comprehend how to equip them.
Pants
The rise on pants is the distance between the crotch and waistband.
passion
Majestic, with passion.