Is Harry a virgin?

Question

Is there anywhere, from JKR's writings to innuendo in books, that implies that Harry had a "serious" relationship before marrying Ginny?

Or was Harry a virgin his whole school life?

Answer 1

Yes

From Twitter:

Is this true? "In 2009, J.K. Rowling announced that Harry Potter lost his virginity in the second half of Goblet of Fire but had to edit it out because her editors said it would cause parents to complain and call Bloomsbury during office hours."

J.K. Rowling: I never wrote it, never announced it & never had it edited out, so it's basically what we British call 'a load of cobblers.'

Now I'm curious, who did he lose it too?

J.K. Rowling: #NeverHappened

How would YOU know?

J.K. Rowling: Fair question. He tells me everything.

Answer 2

There are no indications in the novel that Harry had any sexual relations prior his relationship with Ginny Weasley. The sole indication that he's ever had sex is the presence of his children in the closing pages of the final book.

Answer 3

Their relationship hadn't developed past the "kissing" stage while Harry was still at school.

There is one passage in Half-Blood Prince which can seem to be interpreted as innuendo.

“You’d think people had better things to gossip about,” said Ginny, as she sat on the common room floor, leaning against Harry’s legs and reading the Daily Prophet. “Three dementor attacks in a week, and all Romilda Vane does is ask me if it’s true you’ve got a hippogriff tattooed across your chest.”

Ron and Hermione both roared with laughter. Harry ignored them.

“What did you tell her?”

“I told her it’s a Hungarian Horntail,” said Ginny, turning a page of the newspaper idly. “Much more macho.”

_{Harry Potter and the Half-Blood Prince - Chapter 25}

However, as we see in the next book, their relationship clearly hadn't developed past kissing yet.

“So then I thought, I’d like you to have something to remember me by, you know, if you meet some veela when you’re off doing whatever you’re doing.”

“I think dating opportunities are going to be pretty thin on the ground, to be honest.”

“There’s the silver lining I’ve been looking for,” she whispered, and then she was kissing him as she had never kissed him before, and Harry was kissing her back, and it was blissful oblivion, better than firewhisky; she was the only real thing in the world, Ginny, the feel of her, one hand at her back and one in her long, sweetsmelling hair —

The door banged open behind them and they jumped apart.

“Oh,” said Ron pointedly. “Sorry.”

_{Harry Potter and the Deathly Hallows - Chapter 7}