A study in the journal Dreaming showed that the dreams of people who are in a relationship are 20% about their partners.
Researchers noted that further study is required to see the reasons for dreaming about your partner.
"In order to study factors that might affect the continuity between waking and dreaming, it would be interesting to correlate the frequency of partner dreams with day time measures like intimacy or quarreling," they wrote in the study.
In 2011, a U.K. survey of 2,000 people by Premier Inn showed that exes also frequently make appearances in dreams at least, for men.
That survey showed that about 25% of men regularly dream about their ex-girlfriends, even if they were dating someone else and didn't have feelings for their ex-girlfriends!