On a 4yr old kid seeing my tattoo

Me: *stretching and yawning*
Bella: why do you have a drawing of a heart on you?
Me: drawing? I don’t have one.
Bella: this. *points to my tattoo*
Me: oh yeah, my friend drew it for me.
Bella: which friend?
Me: just a friend
Bella: *gets a tissue and wets it with water*
Bella: *starts wiping my tattoo with the wet tissue* how come it won’t come off? :(