He missed this during the time they were at Harry and Ginny's. And yes the physical pleasure was part of what he missed, a big part of what he missed, but he missed the silent communication they shared in moments like this one. almost right after she untied his hands, he rolled over on his side so she was more comfortable and ran his hand through her hair.
"I don't know what I did to deserve this" he mumbled, closing his eyes as he did so. And he was being honest, he had no idea how he got as lucky as he had. He had a stable, successful job, a nice home (Which he was seriously thinking of moving out of into a bigger one), a beautiful wife and a child on the way. George always believed that good things happen to those who deserved them and vice versa. So he couldn't fathom what good deeds he had done to deserve such great stuff, the George Weasley who he knew to have so many vices didn't deserve it. The good things in his life made him a better person.