I have dealt with a few relationships exactly like this, my best friend for years was like this, and I had to just give up . Some people are socially awkward, or have weird hang ups, and you should afford more lenience in those cases maybe. But I have noticed that some seem to actually get satisfaction from the power of being wanted that way. Like pleasure from 'leaving you on read'. When I was younger in my late teens early twenties this was mostly experienced with new romantic interests acting cool or trying to make themselves a rare commodity, but when that happens in a plutonic relationship I wont even bother with the person..