Why does my dog always look bored/sad when she doesn't have my attention?

I give her attention, I also have another dog that lives with us (shes not alone!). I play with her and walk her etc, but the minute I stop she starts looking bored and sad again. It is REALLY effecting my mood. I dont like anyone (human or animal) looking bored around me. It brings my mood down. What can I do about this? I cant constantly give her attention but I cant stand to see her bored/sad because it rubs off on me! She's a 5 year old Maltese Poodle.