i cant believe how long it took me to think to afflict Poor Edward with hanahaki. He already has the "I'll die without the affection of the person I'm in love with" part, why not also violently cough up flowers!!!
I figure most websites with big lists of flower meanings should probably be taken with a grain of salt, but this one was just too compelling to resist:
Anyway I personally think he would (a) not hesitate to tell you that he has hanahaki disease because of you and therefore you have to love him back, (b) send you flowers he coughed up as a romantic gift & write you poetry about the sensation of flowers filling his lungs, and (c) WORK VERY HARD TO NEVER SHOW SYMPTOMS IN YOUR PRESENCE.