The adjective conjugal describes all husband-and-wife matters, so if someone who is married says, "Single people don't understand how I feel," you can be sure it's a conjugal situation.
The word conjugal comes from the Latin word, conjux, meaning "husband, wife." You’ve no doubt heard of the term “conjugal visits,” to describe private visits between a prisoner and a spouse. But it can describe anything that happens between married people, such as conjugal obligations, which are the things you do to keep a marriage going, or just general conjugal, or married, life.