Recent outings have provoked my thoughtful speculation on the politics of prefixing "my friend" before introducing one's companions. I have a weird sense that the weight of the cue is considerably less pervasive in LGBTQ circles, but maybe I only think that way because of my limited perspective of said circles.
Here is a situation: [Miss A introduces Mister B to Mister C] "Hey, C. This is my friend B."
Good. A counterpoint: [Mister X introduces Miss Y to Anygender Z] "Z, hey, how's it going. This is my friend Miss Y."
I have a theory about this. A theory of coded language. In the first situation, A has introduced B as "my friend" because she wants C to know that B is decidedly *not* her boyfriend, just a boy who is her friend. Translation: "Hey, C. This is my friend B, whom I'm not dating. I'm making the fact clear that I'm NOT dating B because I want you to know that you have a chance." B could indeed be introduced to any acquaintance of A as "my friend": after all, A wants everybody to know that she's available and looking. If A introduces B just as "this is B" to C, she is hoping that C suspects the most and will back off in any unwanted advances.
Now the counterpoint. X, being a heterosexual male, has probably been raised to believe that emotion + masculine = negative connotations. Translation: "Z, hey, how's it going. This is my friend Miss Y. I kind of think I want to date her, but maybe I'm just in it for the conversation, and I'm confused about whether or not she likes me, and I'm not sure how to recognize whether or not what I feel for her is anything more than genial friendship. I'm too much of an emotion-coward to define the relationship at this point, so I will continue to qualify her during introductions as 'my friend' because I wouldn't want her, myself, or anybody else to suspect that something romantically emotional, and therefore bad, might be going on."
Oh, the dynamism of language. I'm not kidding when I say that every example I've ever witnessed of this prefixing phenomenon fits my defining criteria. I defy you to produce a situation (real, not hypothetical) that disproves my theory.
The final word: for women, "my friend" means "my friend;" for men, "my friend" means "my confusion."
[Pam: "Hey, Nico, this is Jim Morrison." // Jim, later, to Nico: "Oh yeah, that's my friend Pam."]