Ex Boyfriend dilemma

Katie • Keep calm and always 🙂
Hey all!  Soooo I need some advice on a couple situations...
1. I've gotten a couple Snapchat videos from my ex, like goofy ones, but we haven't talked since we broke up at all, like not even texted.  So I got one tonight that had the caption "post date night :)" and I'm kind of upset by it and bothered because it makes him look more like a douche and I feel like a loser.  Do I get revenge and send something like that back to him because I just don't care or just leave it alone? 
2.  His birthday is Thursday and I have been contemplating since we broke up whether or not to wish him a "Happy Birthday" or not.  Should I do the polite thing and send him a message anyway?  
Help! Thanks ❤️