Background and release
On August 3, 2017, a highlight medley of the album was released. On August 6, a video teaser was released, showing the group transforming from white outfits to colorful ones. The video also showed each member's name.
The EP was released through several music portals, including MelOn in South Korea, and iTunes globally. On September 12, a limited "B Version" of the album was released physically in South Korea.
"I Don't Like Your Girlfriend" was released as the title track in conjunction with the EP on August 8. On August 1, the first music video teaser was released. On August 4, the second and final music video teaser was released. The full music video was released on August 8 through the group's official Youtube channel. The song debuted and peaked at number 95 on the Gaon Digital Chart, on the chart issue dated August 6–12, 2017, with 21,447 downloads sold.
WEME debuted at number 7 on the Gaon Album Chart, on the chart issue dated August 6–12, 2017. In its second week, the EP continued at number 7 and after a week off the chart, the EP re-entered at number 13 in its fourth week.
The EP also placed at number 14 on the album chart for the month of August 2017, with 28,087 physical copies sold. Also with the release of the B version packaging, the EP placed at number 16 on the album chart for the month of September 2017, with 12,017 physical copies sold. This brought the total amount sold in the first two months to 40,104 physical copies. In its third month of release the EP sold 6,968 physical copies, bringing its total to 47,072.
According to Gaon, the EP sold 47,000 copies since its release, marking the highest selling album by a girl group that debuted in 2017.