Intimacy in that sense is a euphemism. It's not primary meaning of the word: https://www.merriam-webster.com/dictionary/intimacy https://www.merriam-webster.com

Intimacy in that sense is a euphemism. It's not primary meaning of the word: https://www.merriam-webster.com/dictionary/intimacy https://www.merriam-webster.com/dictionary/intimacy