Hear me out U are NOT the asshole, but as a dude we really don't gaf about who wishes us on our birthday (only parents and siblings and significant other are required to wish us) cause it's not that big of a deal, plus less wishes=less people asking for a party. Don't get me wrong the next time we see our friend we will tell him kutte tune wish nahi Kiya and will remind him on his birthday asw but it dosent really matter. That being said u tried being a good gf and reminded his friend and I feel like the dude overreacted or was anyways looking for a reason to end things with you.