Interesting how you would never hear heterosexual men saying that "I hung out with my boyfriends yesterday".
When I was a kid in the 1950s little boys used to say that without any onus on it. My mother continued to use the term to describe my male friends when we were 16-17, and even though none of us would have said it we were not embarrassed by it. Today even gay men would never use it to describe a male friend with whom there was no hint of romance.
British and Australian men can call their male friends "mates," but we don't have a word like that in American dialect. Over here your mate is your wife, not even your live-in girlfriend, The word is much more commonly used for socks. We can talk about our "buddies," which applies only to male friends, but it implies a rather close friendship: someone who would lend you money or help you move, as someone recently defined the terms of a close friendship rather accurately. The guys you meet at the bar after work but nowhere else are not all your buddies. Same for "pals," which is a somewhat older word not as often used any more. We don't have pals of the opposite sex but a guy who wouldn't help you out of a jam is not a close enough friend to qualify as a pal.
When I talk about "my friends" the listener has no clue whether they're male, female or both. Adult women can still use the word "girlfriend" and some do, especially as an interjection: "Girlfriend! Why did you let that loser take you to his apartment?" But I would say it's not even widely used any more by women. Women talk about their "friends" and we can't guess their gender unless the context gives a clue.
Apparently modern Americans have reached a point where it's unremarkable for everyone to have friends of both sexes without needing to distinguish them. At one extreme, even in the bar, and at the other extreme, even if they'd bail you out of jail.