I recommend you to check the relevant section of the FAQ, which contains both specific discussions on homosexuality in Greece and Rome as well as more generic questions of 'homosexuality' throughout history that can be very eye-opening (I know they were when I first read them!)

simply put they didn't treat them in any way. The classification didn't exist then (just as the middle ages dealt with people who committed sodomy as opposed to a class of people called homosexuals). the longer answer is the FAQ provides a good description of this stuff.

very nicely. If you know what I mean.