Talk about unholy -- a Brazilian priest was reportedly caught hiding the fiancée of one of his parishioners in his home!

Check out the video ... shirtless priest Rev. Luciano Braga Simplicio was confronted by some PO'd men at the parish house of Our Lady of Aparecida Parish earlier this week.

One of the angry men busted down a bathroom door to find the woman balled up and hiding under the priest's sink. Someone dragged her out ... and she lay there, seemingly too stunned to speak.

Simplicio reportedly snuck her in early that morning when the woman's husband-to-be was out of town last week, per the blog Pelo Bem de São José .

But that's not what the priest says happened -- he reportedly tried claiming he offered up the bathroom for the woman to shower after work out of the kindnes

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