MCM is an abbreviation for “man crush Monday” on social networking sites. Males either post pictures of themselves or women post pictures of males with a hashtag followed by MCM on their accounts.

As of 2014, over 44 million photos have been tagged with MCM on Instagram. Other Instagram hashtags popular on certain days of the week include “woman crush Wednesday” as WCW, similar to MCM, as men tend to post pictures of women on their Instagram accounts. “Transformation Tuesday” is used as TT in hashtag form to view people’s progress with personal goals, such as fitness. “Throwback Thursday” is the most popular hashtag day as of 2014, with users posting pictures from the past tagged with TBT.