Fred willingly let her pull off his shirt. When she stopped kissing him, he touched their foreheads together, his breathing staggered. This was wrong. He was not looking forward to telling George, which, yes, he had to tell him that he slept with Ang. Because he knew that was what was going to happen. He could only imagine hiw his brother would react, and the thought slightly terrified him.
But then he looked at Angelina again, and he knew despite whatever fear he had of his brother, he wouldn't regret it. Not for a moment. It was that thought that made him pull her lips to his again. His hands went to her bum and he stood up with her still his arms, thankful that his roommates weren't home at this particular moment.