Jennifer Hudson was the lucky gal to sing a sexy rendition of “Happy Birthday” to President Obama for his big 50th bash, but an insider reveals the First Lady was “horrified” over the performance. Say what?

The source says Jennifer was acting appropriately, but Barack was enjoying her performance a little too much and “was acting like a liquored up frat boy at a strip club.”

“When Michelle and Barack got back to the White House, she read him the riot act.”

Ha! Come on, I really don’t believe this shiz. Michelle Obama has her man on lock down and a cutie like J-Hud can’t get in the way. This is the White House, not high school!

Photos: Fame, WENN