What is the connotation for gay蜜 and 闺蜜? What is the connotation for gay蜜? Is the connotation literally that the two guys that it refers to are gay, or is it like the english 'man-date' where it is just two close friends going to do something together.

Same question for 闺蜜.

Is this usually used for young adults (18-30 years old)?
gay蜜 is not a formal word, usually used on Internet or in oral languages by the young.

When a girl has a gay male close friend, she will call him "gay蜜".

e.g. "他是我的gay蜜。" means he's my close friend and he's gay.

Is "gay蜜""闺蜜" usually used for young adults (18-30 years old)? Yes.