There are many different ways to describe the act of intercourse, and using synonyms can help add variety and nuance to your writing or speech. Some possible phrases to use instead of "had sex" include "made love," "hooked up," "had relations," "got intimate," "did the deed," "got it on," "had a romp," "had a fling," "engaged in sexual activity," "had carnal knowledge," "copulated," "made whoopee," and "had a tryst." Depending on the context and tone of your communication, some of these phrases may be more appropriate or effective than others.