Reluctant

[Britney]

Striving against; opposed in desire; unwilling;
disinclined; loth.

[Tina]

Not [in the mood], disinclined.

[Cami]

[unwilling] and [hesitant]; disinclined.

[Monty]

[The strong] urge to not do whatever you had planned (or what had been planned for you) with or without [valid] [reasoning]. Often fails to prevent the occurrence of said plans.

[Justin Bieber]

not willing to do something and therefore slow to do it: