Probably all the more reason, to let go of the idea of him, at this point. Maybe he sensed this, in the first place, but I am not him. I really don't know why, and can't give much more speculation. I do know, he ignored your birthday. I wouldn't want relations with a person, that would disregard a special day, like that. (there are those in this world, who'd rather pass that day by each year, for their own reasons, but you mentioned it in a previous post, and I gravitated to that statement, by virtue of I'd be miffed about it.)

If he doesn't acknowledge your birthday, as he may have in the past, then he's not showing towards you a sense of cherishing you as a close friend.

Which leads me right back to the thread title, 'how can you get someone to stop ignoring you without seeming desperate or clingy?' The more contact without reciprocation, the more socially awkward things start to appear.

I've developed an internal rule of thumb. When in communication, texting/email/phone, I try to maintain a ratio of 1:1. I don't veer off a 2:1 ratio. (lest it's a more involved back and forth texting 'conversation', then numbers don't quite matter, so long as it's a back and forth texting. ) For me, going over that 2:1 ratio, isn't giving the other person the benefit of the doubt. And over that ratio, leaves me, feeling a bit unbalanced, a bit lopsided. I have to question myself, if I am putting too much effort without a return.

If I don't hear from certain friends for weeks at a time, and believe me, that does happen, I chalk it up, to the business that we all experience.

I've been in a socially awkward situation. Believe me, knowing what was said, about that unbalanced relationship, about me, was the most embarrassing, shaming, humiliating experience. Instead of just breaking it off, no contact, that 'friend'/'boyfriend' decided to ignore, ignore, ignore, then...call...hey, I need to talk to you, you are the only one who understands my family life and my dad is ill, etc. Then, ignore, ignore, ignore...

...until he broke it off via email, having spent the week with someone else, at another college, but then I still, like a schmuck, typed up all his finals papers, so he could graduate...then he married her.

It was humiliating, because then, he later in the decade, after I stopped all contact, vilified and blamed me for a large part of his troubles. So, this guy of yours, clearly isn't being clear and concise with you. In some cases, relationships/friendships need to end in an all or nothing manner, because there is something 'amiss' about the connection to begin with.