Bernie Sanders fans ­really give a shirt about campaign merchandise.

A Park Slope boutique has been on the receiving end of threats and unwelcome political lectures — all for selling Hillary Clinton T-shirts.

A week before the state’s April 19 primary, Items of Interest owner Susie Kurkowski offered “Hill Yeah!” and “Vote for the Girl” shirts, Clinton coloring books and Hillary dolls.

At first, Sanders supporters asked where the Fifth Avenue store’s Bernie shirts were. But after he lost the New York primary, conversations turned aggressive.

“One man stopped outside as I was putting up a sale sign and said we ‘should die for supporting a murderer. She’s a thief,’ ” sales clerk Stephanie Henry said. “He had Bernie buttons on his backpack.”

In April, a customer came into the store and lectured Henry about Clinton’s criminal-justice record.

“She said I shouldn’t support Hillary because she ‘hasn’t done anything for the black community’ and we’re ‘sheep’ for going along with Democrats,” said Henry, who is African American.

Last week, one passer-by shouted that Clinton should be indicted.

Kurkowski and her sales associates have also scrubbed Bernie supporters’ political rants about the shirts from their store’s Instagram page and other social-media accounts.

She said she “felt terrible” about the complaints but noted it wasn’t surprising the shirts sparked political debates among shoppers.

“Park Slope is very socially conscious neighborhood,” she said. “They’re informed and engaged in this dialogue.”

Despite the backlash, the shirts have sold well, more than 200 in the past month, Kurkowski reported.