Textual Clues to Dumbledore's Sexuality

"Nothing like this man had ever been seen on Privet Drive. He was tall, thin, and very old, judging by the silver of his hair and beard, which were both long enough to tuck into his belt. He was wearing long robes, a purple cloak that swept the ground, and high-heeled, buckled boots. His blue eyes were light, bright, and sparkling behind half-moon spectacles and his nose was very long and crooked, as though it had been broken at least twice. This man's name was Albus Dumbledore.
And he was totally, completely gay."
— Harry Potter and the Sorcerer's Stone, p. 8

"A jet of steam had hissed out of the camera. Harry, three beds away, caught the acrid smell of burnt plastic…
'What does this mean, Albus?" Professor McGonagall asked urgently.
'It means,' said Dumbledore, 'that the Chamber of Secrets is indeed open again.'
Madam Pomfrey clapped a hand to her mouth. Professor McGonagall stared at Dumbledore.
'But, Albus … surely … who?'
'The question is not who,' said Dumbledore. 'The question is … who wants to join me for Bear Night at the Man Factory this Friday? Anyone? Come on! Three-dollar Bud Lights!'
— Harry Potter and the Chamber of Secrets, p. 181

"It was a map showing every detail of the Hogwarts castle and grounds. But the truly remarkable thing were the tiny ink dots moving around it, each labeled with a name in miniscule writing. Astounded, Harry bent over it. A labeled dot in the top left corner showed that Professor Dumbledore was pacing his study. He was, Harry realized, most likely thinking about how extraordinarily homosexual he was."
-- Harry Potter and the Prisoner of Azkaban, p. 193

"Harry bent closer, his head right inside the cabinet. The silvery substance had become transparent; it looked like glass. He looked down into it, expecting to see the stone bottom of the basin – and saw instead a young Albus Dumbledore, intently frenching with some other dude."
— Harry Potter and the Goblet of Fire, p. 584

"Professor Dumbledore's dress was unusual that morning. Instead of the traditional scholarly robes, he wore a t-shirt that read, 'I'm not gay, but my boyfriend is. (But, seriously, I am actually gay.)["I," in this case, meaning me, Professor Albus Dumbledore. Really, really, really gay.]'"
— Harry Potter and the Order of the Phoenix, p. 342

"Harry sat in seething silence, glaring at Dumbledore. What was going on? Did this mean that Dumbledore had indeed ordered Snape to find out what Malfoy was doing …?
'So, sir,' said Harry, in what he hoped was a polite, calm voice, 'you definitely still trust--?'
'Harry,' Dumbledore snapped. 'I must tell you something immediately.' He took a dramatic pause and stroked his beard. 'I'm gay, Harry. I'm sexually attracted to other men. There, I've finally said it.'
Harry sighed. 'Yes, sir, I know.'
'You do?'
Harry rubbed his forehead in disbelief and frustration. 'Sir, everyone knows. You've made it abundantly clear. Now, can we…'
Dumbledore slammed his open hand against the desk. 'Everyone knows?'
'Yes! Everyone! How could you expect even a single muggle in the entire country not to know? With that ridiculous t-shirt you wear all the time now, and your Magical Queer Studies class that you started, and the Men of Diagon Alley calendar on the wall right over your shoulder. Not to mention that stupid nickname you've been trying to get everyone to call you…'
Dumbledore's mouth dropped open in shock. '"Dumblefabulous" was my mother's maiden name!'
Harry shook his head and leaned back in his chair. 'Whatever.'
A moment of tense silence passed. Dumbledore shoved his hands in his pockets and hung his head. Slowly, he looked up at Harry. 'I suppose you hate me now?'
Harry buried his face in his hands. It was going to be another long night."
— Harry Potter and the Half-Blood Prince, p. 358

"THE END (but not of Dumbledore's remarkable gayness)"
— Harry Potter and the Deathly Hallows , p. 749