SPURNED LOVE JOE SCORES BIG DOUGH

TAYLOR SWIFT is furious ex-boyfriend Joe Alwyn is making a mint as co-writer on some of her tunes — because she feels the publicity-shy actor barely contributed, sources snitch. 

“Fair or not, it’s made him a VERY rich guy,” an insider shares. 

Alwyn, 33, is credited under the pseudonym William Bowery on three of Tay-Tay’s albums for six numbers — including Betty, Champagne Problems and Sweet Nothing.