It's not my fault

I beat my little sister.
Oh yes, I swear it’s true.
I’ve tried to stop, but really,
It’s impossible to do.
I only beat her once a year,
So please give me a break.
It hurts me more than it does her,
It makes my heart just ache.
But beatings shall continue
Up until the day we die.
September means I’m one year older,
Hers is in July.
July precedes September,
Yes, it’s factually true.
But alas, the difference in our ages
Always will be 2.
I beat my sister age-wise.
I beat her every time.
She’s always 2 years younger.
She’s always in her prime.
Here’s to my little sister!
She’s 50 years today!
No matter how she ages,
I will always lead the way...

HAPPY BIRTHDAY!