I have 3 gliders right now. (2 males and 1 female) I have 2 males because one is the offspring of the other 2. The baby male is about 10 months or so, the person I got them from didnt specify. My girl is now pregnant again. I have been reading things online just to be prepaired im ready for this joey, but ive been reading trios are bad. Im not sure what I should do. Any advice?

Neuter the males before the joey(s) are out of pouch. Neuter any male joey(s) if you plan to keep the colony together. Trios aren't 'bad' but with two intact males there is a possibility of complications (as there would be in any colony). You also don't know if the son mated with the mom. The inbreeding could cause health issues with the joey(s) as well as a higher likelihood of rejection (if the female senses something is wrong). Neutering will stop any further inbreeding and allow you to keep your colony together if all goes well.