She-Hulk: Attorney at Law has definitively answered the question of whether or not Captain America died a virgin. It’s a fan theory that’s been turned into a running gag on the first episode of She-Hulk, where main character Jennifer Walters continually tells anyone who’ll listen that Captain America died without first having done the deed.At the end of the episode, Bruce Banner (aka He-Hulk) cuts Jen’s drunken tirade short with the definitive answer: "Steve Rogers is not a virgin. He lost his virginity to a girl in 1943 on the USO tour." Having finally been proven wrong by someone who would know, Jen ends the episode by triumphantly shouting, "Captain America Fu-."
That’s all well and good, but now that we know Steve Rogers banged at least one woman in 1943, fans have created another theory: Steve Rogers banked Star-Lord’s mom.
The only evidence to support this theory is a clip from the original Captain America showing Rogers on the USO tour in 1943. A woman approaches him, says "hi," and we’re left to wonder what that interaction could have led to. Interestingly, the woman in question is the same actress (Laura Haddock) who plays Star Lord’s mother in Guardians of the Galaxy.
There is, of course, a fatal flaw to this theory in that Star Lord was a kid in the '80s, forty years after the deed was presumably done. It’s possible that superheroes have exceptionally long gestation periods, or that Rogers actually banged Star-Lord’s grandmother. We’ll have to wait for the Marvel Cinematic Universe to release a show which addresses this latest fan theory.
One thing we know for sure is that Captain America himself found the revelation pretty funny.
If you'd like the whole story on how Captain America's virginity became a plot point in She-Hulk, EW has an interview with head writer Jessica Gao where she discusses how that knowledge was disseminated from one Marvel writer to another. And don't believe the misogynistic user reviews--She-Hulk is great, and you should watch it.