Combination of the words 'man' and 'bag' create 'mang' and 'wang' being slang for penis showing their attraction towards peni. This an insult towards anyone who is homosexual, as it refers to their unhealthy attraction towards women's things e.g. hand bags, flowers etc. Also this word can be used instead of gay, homosexual, faggot etc.
Guy1: Have you heard Elton John's new song.
Guy2: No-one listens to him, he's a mang o' wang.
Refers to a certain bitter/sour taste that a mango gives off. Can be used to describe any kind of fruit, not limited to mangoes.
Bob: What's wrong with your mango?
Tom: It tastes weird. Like bitter and sour at the same time.
Bob: Oh, they call that mango wang.
Tom: Now that you mention it, this mango does have some sort of wang to it.