Inside Move to Second.....

[kpbaseball17]

Do you have to throw to second on an inside move if the pitcher turns properly and steps toward the bag properly. I used this move frequently while pitching in high school and college and never had a balk called. Today however, I got in an argument with an ump about it and he called it a balk on us when our player did it without throwing. We are using MLB rules. Please help!

kbp