![1boy 1girl black_choker blush bouncing_breasts breasts capelet choker christmas closed_eyes cowgirl_position cum cum_in_pussy drill_hair fur-trimmed_capelet fur_trim girl_on_top hair_ornament hetero highres idolmaster idolmaster_cinderella_girls jakelian kanzaki_ranko lips long_hair medium_breasts motion_lines navel nipples no_bra overflow panties panties_aside parted_lips penis pussy red_capelet sex side-tie_panties silver_hair solo_focus straddling sweat tears thighhighs twin_drills twintails underwear vaginal white_panties rating:e score:45 1boy 1girl black_choker blush bouncing_breasts breasts capelet choker christmas closed_eyes cowgirl_position cum cum_in_pussy drill_hair fur-trimmed_capelet fur_trim girl_on_top hair_ornament hetero highres idolmaster idolmaster_cinderella_girls jakelian kanzaki_ranko lips long_hair medium_breasts motion_lines navel nipples no_bra overflow panties panties_aside parted_lips penis pussy red_capelet sex side-tie_panties silver_hair solo_focus straddling sweat tears thighhighs twin_drills twintails underwear vaginal white_panties](/cdn_image/preview/e8/a2/e8a24c5392d4cb0f5ad21a698b4825fe.jpg)
Refers to breasts in motion, often as part of a .gif or flash animation. If it is not an animation, something like a motion blur or movement lines must be present to convey a sense of movement.
If one breast is up and the other is down, add the unaligned breasts tag as well.
Example: post #694780.
This tag implicates breasts (learn more).