some one who achieves the ranking of a duche bag and a fucker in one fucking duchey act

It's actually 2 expressions combined, duche bag (- historically known as an instrument of cleanliness bestowed upon a dirty piece of female genitalia) and fag(Short form for faggot aka homo).

This expression is used when a duche male is sleeping with a lot of other men. He's like a male - gigolo, for men!