Unbuttoning his shirt, he came and knelt in front of her and gently tugged the towel away from her. With a sound of pleasure he kissed and sucked at her nipples. They felt tender, more sensitive than usual. His tongue filled her with an ache, a strange, almost unbearable feeling.

‘Don’t!’ She pushed him away, though not roughly.

He looked up startled. ‘What’s up?’

‘They hurt – I don’t know why.’

‘Oh, sweetheart . . .’ This seemed to arouse him, and soon he was naked and drawing her down to lie beside him. He lay looking down at her. ‘You know, I think they’ve got bigger.’ Gently he caressed her breasts and the feeling went through her like electricity, a mixture of pain and desire.

She knew he was right. ‘Must be something to do with the time of the month,’ she said quickly.

‘I thought you didn’t seem quite yourself today.’ He kissed her cheek, then beamed down at her. He was already fully aroused. ‘My poor Katie. But God, you are so beautiful.’

He kissed her lips then and soon went to move his hand between her legs, in a hurry, wanting her to be ready for him.

‘You’re not . . . ?’

‘Bleeding? No.’ If only she was!

When he came in naked, jerking with urgency, with no horrible-smelling rubber thing covering him, she didn’t protest. It was too late now, after all. It had happened before, a number of times. The first time she hadn’t noticed until it was far too late. She left all that up to him.

‘I took a risk,’ he’d said afterwards, sort of in apology. He grinned winningly at her. ‘It’s just – it feels so nice, just delicious. It’s like dying and going to heaven.’

Katie blushed. She found talking about all these sorts of things very awkward, and when at other times he had neglected to protect himself and had plunged into her, she had been too embarrassed to say anything. He seemed to need her so badly as well, and it felt wrong to stop him.

Now she lay back and felt a hot sweep of desire growing in her belly as he moved inside her. It was not quite like anything she had ever felt before, and after he’d climaxed she felt angry and unsatisfied.

‘Don’t go,’ she ordered, pulling him close in a way that took him by surprise, and moving under him she brought herself to a shuddering, gasping climax, not quite like any she had ever had before, as if her insides were in a melting, volcanic state.

‘My God!’ Simon said, excited by her reaction, and thrust into her again. At last they both lay back, panting.

Katie felt like spilling words all over him. Do you realize – do you know what you’ve done, what we’ve done? Oh, hold me, hold me and tell me you’ll stay with me and it’s all going to be all right!

But she didn’t dare. The words, once spoken, could not be taken back. She was going to have to keep her secret – for as long as she could.