When they first began their "relationship" Gaara found undressing Lee to be a chore, an unnecessarily complicated and downright annoying affair. He simply couldn't fathom why someone as skilled and intelligent and Lee wore such strange and impractical clothing.
Against all odds, Gaara slowly became first accustomed to, and then fond of Lee's uniform. It had its upsides after all. In a sea of beige and brown and black in Suna, Lee's bright green and orange ensemble stood out and made him easily recognizable and thus found. It also showed off Lee's firm, toned body that Gaara so enjoyed having in his bed at night.
Undressing Lee eventually became a sort of ritual for Gaara, a way to help them both unwind from the stress and danger of their lives as high-profile shinobi. Each piece was carefully removed and stored in its proper place before moving to the next. Gaara's favorite part came at the end when he unwrapped the bandages from Lee's strong, muscled arms and calloused hands, capable of dealing out punishing blows and tender caresses in equal measures. Once everything was stripped off, they were just Lee and Gaara, two outsiders who loved one another with uncommon depth and understanding.