A man who has obtained status of having a lot of Mangoes. It is believed that most of the time it’s just a rat who disguises themselves as a human with Mangoes.
A real cool guy. He is much cooler than you. He's a little bit gay-ish. He's hot n sexay. He owns your ass and thats all you need to know! Bow down to him now..BITCHES!
You see in this context a the ‘man-go-boom’ means your broski has just done something epic or funny, meaning the approval is like they are ‘ da bomb ‘ their core equating his comment to a good one , ... ( This comes from the Latin contex: “ horminem ire BUTIO”)