Being sexually excited by a partner wearing clothes rather than being naked.
People who enjoy this kind of sexual arousal are known as “clothing fetishists”.
Clothing fetishism is one of the most popular and widely accepted forms of sexual expression today, and many people find it an exciting way to express their desire. The endytophilist is more turned on by his partner clothed than naked. Often, the fetishist would also prefer to wear clothes (than to be naked).
On the Internet, there are many websites with so-called "no-nude" porn. Often seen in connection with "dry-humping", where the parties rub themselves and the genitals against each other with clothes on.
A well-known dry-hump scene with Cameron Diaz and Justin Timberlake in the movie "Bad Teacher": https://www.youtube.com/watch?v=LeeyK8_-Ej0