As far as I know, the word "girlfriend" in Russian is ambiguous. As well as the word for "female friend".
If I say ты хорошая подруга am I telling just "you're a good friend" with no ambiguity?
If I say я хочу, чтобы ты стала моей подругой is it evident that I am telling "I want you to become my girlfriend"?
Being a man, does the usage of the word подруга imply a connotation with "girlfriend"?
if I just want to tell "friend", the word друг works for both genders, right? If I say ты хороший друг it can mean "you're a good [female] friend", right?
я хочу, чтобы ты стала моей подругой- implies a "relationship upgrade", and due to this implies some romantic interest (even if technically going from aliens to friends is a huge upgrade even in asexual ways). Then "я женатый человек, но у меня есть десяток подруг" would more often NOT imply romantic interest, would more often be about "my wife trust me to have female friends, and I do not abuse that trust". So there is clear connotation with "can there be a friendship between male and female?" stereotypical question. There is a POSSIBILITY of romantic interest conveyed. – Arioch Jun 22 '18 at 10:26