Marriage.

Hi can someone help me, me and my boyfriend have been together now for 7 month. Thing is, he is still married. They have been separated for well over a year now and his ex has a baby with someone else. I asked the other day if they were planning on getting a divorce, he just said that they are waiting until the time has passed for it to become annulled, whatever that means, I have never been married. Lol. Does anyone know how long this is after they have been separated? Thanks