I am working on updating my résumé. I am employed full time (and have been for over a decade), but the last three years I've also done some contract work on the side. I am very careful to keep the two separate. When I am at my full-time job, it has all of my focus and I make sure the job is getting done. The contract work is limited to nights and weekends.
I would like to list the contract work on my résumé. The work allowed me to gain experience and skills in areas that wasn't possible at my full-time job. I feel like that experience makes me more valuable as an employee, but I am concerned that it might be seen as having "split loyalty", even if the work was done on my own time.
Is there any advice on how to handle this situation? Perhaps an explanation/wording I should put on the résumé or something I should say in a potential interview?