A mother's guilt

I sit her tonight, alone, without my children. I am feeling guilty for not being with them. I know that this isn't necessarily a rational thought. They are with their father, who also loves them dearly. I have given of myself time and time again for my children. They are my world, and almost every hour (outside of work) is spent with them. Yet, in these hours alone in our home, I miss them. And I feel this gnawing inside of me that says I should be with them. Part of it may be the guilt of enjoying my time alone, enjoying my time not partaking in the chores of mothering. But it is the cuddles I miss most, and the sassy chat of my pre-teen. I hope they know in their hearts that their mom misses them.