"Dorian! Dorian, could I have a word?" Dr Sam Bayfield hurried out into the College quad in pursuit of his colleague.

The Professor of Art History turned, smiling. "Hello Sam. What's up?"

Bayfield lowered his voice. "Could I have a word in private, do you think? I'd like your advice about something. Something rather sensitive."

"Of course. Come up to my rooms."

The two men settled themselves in the Professor's study, overlooking the quad, where wisteria hung on the archways of the cloisters, pale purple against the honey-gold stone. Dorian poured two glasses of port, and handed one to Bayfield.

"Now, what's the matter, Sam?"

Bayfield looked uncomfortable. "Look, Dorian, before I tell you anything I have to ask you to keep this conversation absolutely confidential."

"I'll keep it confidential if I can. You haven't committed some heinous crime, have you?"

"No, of course I haven't. But I have been – rather foolish." Bayfield sipped his wine, and placed the glass on the table by his chair. "Dorian, half your students are in love with you. How do you cope with that?"

Dorian laughed. "I think 'half' is an exaggeration, Sam."

"But how do you manage?" Bayfield persisted. "I mean, how do you keep it from becoming a problem? Some of them flirt with you shamelessly. I've seen them."

Dorian fixed his colleague with a concerned gaze. "Sam, what's this about?"

Bayfield stared up at the ceiling, searching for the right words. "Look, it's common practice for tutors to mix socially with senior students. Friendships aren't uncommon. Some academics form lifelong friendships with their students, to their mutual benefit." He broke off. "God, I'm rambling. There's no excuse for this."

"What have you done, Sam?"

"Peter Renishaw. One of my Doctoral students. Christ, Dorian. I slept with him." Bayfield covered his face with his hands.

Dorian's throat constricted. Bayfield was a close friend, a good colleague. He was a discreet man, respectful of others. It distressed Dorian to see him racked with guilt and fear.

Silence hung between them for a few moments.

"I slept with one of my Professors when I was a student," Dorian said in matter-of-fact tones. "Nothing came of it. We remained on good terms."

"With respect, Dorian, that was the 1970s. Different times. These days, if you touch one of your students, the Moral Police will hang you out to dry." Bayfield buried his face in his hands again. "Christ, when this gets out, I'll be sacked. There'll be an inquiry. I'm finished."

Dorian topped up his friend's glass, and then his own. "So, what does Renishaw say about it? Has he made threats?"

"No. Well, I haven't seen him since. It was only last Friday."

"How old's Renishaw?"

"Twenty-five, twenty-six."

"Get this in perspective, Sam. He's an adult. He's not under age; you didn't coerce him. The student-teacher relationship muddies the water, but essentially, you're both consenting adults and you made a choice. Stop crucifying yourself, Sam. Most likely it will come to nothing."

Bayfield picked up his wineglass again. "Have you ever—? Has this ever happened to you?"

Dorian smiled faintly. "No. I know there's been speculation in the past. You said it yourself – some of the students flirt with me shamelessly. It's always been the way. But I never do anything about it."

Bayfield tried to smile. "Faithful to some well-loved husband you've got hidden away somewhere?"

His colleague shook his head. "No, Sam. No hidden husbands. I don't sleep with my students; I don't sleep with anyone. I'm celibate."

Bayfield looked incredulous. "I don't believe you."

"It's true." Dorian shrugged. "Sex isn't everything. By the time I was thirty, I was well and truly married to my career. All these gorgeous, bright young things we work with could be a huge temptation if I let them, but I don't. I haven't slept with anyone for more than ten years, Sam."

Dorian sipped his port.

"You know, Sam, Universities began as branches of the Church. For hundreds of years, if you were a member of a University, you were expected to be celibate. You could say I'm just following tradition."

"Not many people would want to live that way today, Dorian."

"Perhaps. But when I first joined the Fine Art faculty, I struggled. It was hard, deciding who I could keep company with, and who was out of bounds. So I made a decision – I stopped having sexual relations with anyone. It was hard at first, but I got used to it. Now, I wouldn't know how to go back to the realm of sexual negotiation."

Bayfield shook his head. "I admire your courage. I wouldn't be able to do that, Dorian."

His friend laughed. "Nobody would ask you to, Sam. Look, don't agonise over what happened. In all likelihood, nothing will come of it. You'll have to face Renishaw sometime, seeing he's your student, but you're both adults. You can work it out."