Bills' Isaiah McKenzie Does Gender Reveal For Sister After Scoring TD

Isaiah McKenzie earned major props from his fantasy owners AND his family with his TD on Thursday night ... 'cause it turns out the Bills wideout did a gender reveal for his sister right in the middle of the endzone after scoring!!

Buffalo just made the revelation in a TikTok video posted Friday morning ... showing the slot receiver actually screaming out "It's a boy!" into a camera right after recording a touchdown in the third quarter of the Bills' game against the Rams.

In the video that the Bills shared, you can see McKenzie's family watching on the TV as he revealed the news.

And, when he yelled into the lens -- they went bananas!!!

It's unclear whether Isaiah planned the gender reveal or if it was a surprise ... but his family's reaction was priceless, bringing smiles to their faces.

Of course, McKenzie, his fam, and the Bills had a lot to smile about Thursday ... 'cause they knocked off the defending champs in a laugher, 31-10, at SoFi Stadium.