What are the chances that Captain America, by the end of his tenure in the Marvel Cinematic Universe, remained a virgin? We see the hero's decade-spanning arc, starting as a scrawny young man and ending as the literal savior of multiple realities. However, the movies only saw him kiss two women, and he never even dated before Captain America: The First Avenger. So did he ever go further afterward?
In all likelihood, probably not. When looking at Captain America's history throughout the MCU, there are numerous points where he might have had sex, but there are two specific instances where it most likely could have occurred. In the first instance, Stever might've been stopped by his loyalty to his first love, Peggy Carter. With the second instance, his time spent running from the government could have prevented him from having the opportunity.
Between The Avengers and Captain America: The Winter Soldier
The first period Captain America could have had sex is between The Avengers and Captain America: The Winter Soldier. After being unthawed by S.H.I.E.L.D., Captain America spent most of his time brooding until Nick Fury encouraged him to join the Avengers. But after The Avengers, where did Cap go?
Steve went on to work for S.H.I.E.L.D. He was issued an apartment, where he was monitored by Sharon Carter, and it was clear the two had chemistry. But because the pair didn't share a kiss until Captain America: Civil War, it's extremely unlikely the two had sex. However, Black Widow continuously tried to set Cap up for dates, but he seemed to turn her down every time.
Considering Natasha's relationship with Bruce Banner at that time, it's also unlikely that Steve had any relationship with her, even though they kissed in Captain America: The Winter Soldier. However, Cap also tells her that their smooch was not the first time since being frozen that he kissed a girl. This indicates that he had some romantic endeavors that may or may not have culminated in intercourse; however, Steve might've been lying, meaning he was possibly still a virgin at the end of The Winter Soldier.
Between Captain America: Civil War and Avengers: Infinity War
The next period of time Captain America might've had an intimate relationship was between Captain America: Civil War and Avengers: Infinity War. Rogers simply did not have enough time for a relationship between The Winter Soldier and Age of Ultron, and he was too busy leading the Avengers in the lead-up to Civil War to form a relationship.
While Black Widow will explore this nebulous period of time in more detail and Falcon and The Winter Soldier might go into Sharon Carter's relationship to Steve more intimately, it's clear that following their kiss in Captain America: Civil War, the two probably had some sort of relationship. This is most likely when Cap lost his virginity.
Beyond that, the likelihood of Steve remaining a virgin decreases even further. It's highly unlikely that Steve didn't have a relationship with someone after Thanos eradicated half of the universe's population, seeing as how he spent time trying to bring people together during the years that followed. The chances of him remaining a virgin decrease even more after he traveled back in time to start a life with Peggy, since it's very difficult to believe these two people in the prime of their lives didn't have sex. So no, Captain America is certainly not a virgin by the end of his run in the MCU, but he probably was for most of Phases 1 and 2.