"Boys and girls, I'd like to introduce you to J.J. Watt, as if you don't know him", Keefe told her current fourth grade students after Watt just showed up.
J.J. Watt's fourth-grade teacher, Mrs. Keefe, is retiring after 41 years, and the National Football League star surprised her by popping into her classroom with a big cake.
She was surprised to see her former student and the kids in class rejoiced as he came into the room.
The teacher and her former student cut the cake together and served it to Keefe's students, who could barely contain their excitement.
In the visit broadcast on Facebook Live, Watt said the soon-to-be retired Mrs. Keefe was one his "favorite teachers of all time".
The Houston Texans star surprised Mrs. Keefe with cake, a pair of shoes from his Reebok line and a trip for her and her husband to attend the J.J. Watt Charity Classic in Houston next month. "Whatever you want to do, you can do it".