Paige Harden of The University of Texas at Austin said the study found those who had a later first sexual experience were less likely to be married and had fewer romantic partners in adulthood.
Harden said it's possible people who have their first sexual encounter later might be pickier in choosing romantic and sexual partners, but more research is needed.
"Most people experience their first intimate relationships when they are teenagers, but few studies have examined how these adolescent experiences are related to marital relationships in adulthood," Harden said in a statement.
Harden and colleagues used data from the National Longitudinal Study on Adolescent Health to look at 1,659 same-sex sibling pairs who were tracked from around age 16 to about age 29. Each sibling was classified as having early sex at age 15 or younger, having sex on-time at ages 15-19, or having sex late at age 19 and older.
The study, to be published in the journal Psychological Science, found among the participants who were married or living with a partner, people with later sexual initiation were more likely to say that they were happy with the way they and their partners handled conflict, that their partners showed them love and affection and that they enjoyed doing day-to-day things with their partners.