If you are the employer, you should consult your lawyer and see what issues are at stake.
If you are the employee, either the gay one or the straight one, you might also consult a lawyer to see what issues are at stake, or you could talk to your manager or human resources if you feel comfortable doing that. If there is an LGBT organization within your company, or in your town, contact them for further advice as well.
sick is like my friend asher he is gay
Be very wary of labeling people. Just because a male coworker may have effeminate mannerisms doesn't mean he is gay. However, if he is then he may feel lonely and just wants to be your friend. Many gay men have several female friends because they are more comfortable with them. Cut him some slack and be pleasant to him and get to know him a little better. If he's gay it's sure not love he's after.
Probably not, unless you know for sure they are gay, in which case... maybe!
Leon
You can only know for sure if he tells you he's gay.
not unless she tells you she is...
No one knows until he comes out and tells the world he is gay
As of 2016, you can be fired for being gay in 29 U.S. States, but not in the UK or Canada.
you can't unless he tells you himself.
The eyeliner he wore tells me yes.
you comfort him and tell him you respect his decision.
Yes, it is legal, but it it is rude and it wouldn't matter anyway. UK employers cannot fire someone for being gay.