DISCLAIMER: We don't do birthdays or holidays to keep the stress level down and the circus from coming to town. I turned 47 on Tuesday and it was like a state secret, which is how we like it, so my opinion is heavily skewed by my practices. You might as well stop reading this post right now.

He's a boyfriend of ten months, not a fiancee or a step-dad. I'm betting that your son didn't expect anything from him. Your boyfriend did have a good opportunity to advance his position: he obviously would have scored major appreciation points had he given your son a birthday gift, but I do not think that it reflects particularly poorly on him that he didn't give a gift: he simply missed an opportunity. You'll have plenty of other things to hold against him later.