When you post a picture of a woman with whom you have a crush (usually a celebrity) on your social media sites.
Crush Wednesday is considered an Internet theme day, observed
every Wednesday, during which people (men and women) post pictures of the
women they like on their Facebook, Twitter, Tumblr, Instagram, etc.,
accounts. You'll often see the hashtag #womancrushwednesday trending
online, indicating a lot of people are posting their crushes.