Hilary Duff found herself in major heat after she and boyfriend Jason Walsh rocked not-so-appropriate Halloween costumes over the weekend.

The singer and personal trainer attended a Halloween party— and made their official debut as a couple — while dressed as a sexy pilgrim and Native American chief. The costumes weren't well-received on social media, as the two were blasted for cultural appropriation and promoting negative stereotypes.

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"I can't believe Hilary Duff looked at her boyfriend and thought 'Yes this costume is perfect and not offensive,'" one Twitter user wrote.

hilary duff and jason walsh

The 29-year-old later posted an apology via Twitter in response to the backlash, writing, "I am SO sorry to people I offended with my costume. It was not properly thought through and I am truly, from the bottom of my [heart] sorry."

The backlash comes less than two weeks after Hilary confirmed her relationship with the personal trainer.