1) Dash and Mac's first child was born as a girl and he grew close to his Dad.

2) Growing up, Thunder wanted to be just like his Dad in every way. He wanted to be big and strong like him. But, his parents were noticing small things like how he always wanted his hair cut short. And how he never wanted to be perceived as a girl.

3) As the years went by he realized that he was a stallion not a mare. He nervously told his parents about and they were proud of Thunder. Now, he got a haircut that fit him and he got a magical transformation to change into a stallion.

Oh and the pink pony is Cadence and Fluer de lis daughter. I just haven't named her yet. She cut his hair.

*edit* I'm sorry about the misgendering mistakes I made. I never meant to offend anyone at all. I am so sorry. Thank you artinandwritin8 and :strawberry-spritz I never who have thought of that before. So, I'm glad ya'll corrected me ^{^}