MLB All-Star Game MVP Shane Bieber is on one helluva hot streak right now -- not only is he one of the best pitchers in all of baseball ... his girlfriend is insanely attractive!!
The Cleveland Indians ace wished his lady, Kara Kavajecz, a happy birthday on Thursday ... saying "Man ain’t she somethin?! Cheers to this beautiful birthday girl. I love you!"
Biebs and Kara celebrated the big day with a cute little pizza-making date (take note, fellas).
The couple -- who are both UC Santa Barbara alums -- took their romance to social media in December 2017 .