O///o

.......skirt

Screw the rules, I have a boner.

Danbooru states this as the definition of pettanko/ flat chest:

For Danbooru purposes, girls with breasts roughly one-third of the size of their head and smaller.

Please note the girls part...
Trap tag added, by the way.

... Well, shit. I do believe I must go fap now.

I dont think its a trap. Look at the hair.