putting two boys together near a girl?

So as some back story, I have two chins. Chester is a male and Charlie is a female. Charlie was originally purchased as a friend for Chester, as I found her in a pet store and they weren't taking very good care of her at all so I felt like I had to get her out of there, and they told me that she was a boy so I thought I'd take her home and eventually try to introduce her to Chester. (This was a long time ago, I was around 13 at the time so I didn't exactly think to check while I was there) Anyway while Charlie was still in her 30 day quarantine I noticed she was a girl, not a big deal as I was fully prepared to keep them separately if need be anyway. Chester has always been an exeptionally friendly chin though, and Charlie not always so much. I've been thinking about getting a third recently and while they may need to all be kept separately in the end anyway I'd love to pair them with either Chester or Charlie. It seems to me like Chester would probably be more receptive to a cage mate though, but I know that male chins will fight in the presence of a female. Now I'm pretty sure I've seen people who keep pairs of boys and girls in the same room but wouldn't they fight? Would they have to be kept in a separate room from Charlie? I may end up just getting a girl in the end anyway but I'm just wondering for now. Sorry for the long post!