When my son was in 1st grade he had 2 pull out classes each day. He was also in a reading discussion group 2 times a week. So he was always on the go especially for a 1st grader. On his way back to class from his pull outs he would stop by the library grab a book off the shelf and sit down and start reading. I got a note from his teacher one day stating he had done this. He told me he did this all the time. I told him to check the book out and get back into class. He told me he already had 2 books out already and couldn't check out another till he returned his others.
He said he has read several books this way. He never really got into trouble just something to watch out for. smile

He absolutely adored his librarian his 1st grade year. She let him check out any book he wanted no matter which level it was. I bet she was breaking some rules.