Ferret introducing

Question
So my gf and I have had a ferret that is a 3-4 year old, fixed, male for about 6 months. We didn't know much about his background because he was found by someone and taken to a vet hospital and that's where we got him from. But he is a very sweet little guy. He has an entire room setup for him so we got another ferret the other day as a companion. The new one is a 9 month old, fixed, female. We put her in a pet carrier and let each meet on the floor, that went fine, we let her out and she would chase him and he would hide under a book case and it seemed like they were playing and it seemed like she just wanted to play with him. But now he goes after her and she screams and pees/poops as they roll around so we break them up. He usually has a puffed tail. I know they play rough but this seems too violent. However he has not drawn blood. She now hisses at him and try's to avoid him. We only have one big cage, which is where we keep her, and he stays out in the room and we have supervised play time as well as 1-1 playtime. Also she is a lot bigger then he is but he is the aggressor. We are still switching bedding materials, are going to rearrange the room and put them in the tub together just so they can get wet. We washed them both separately prior to the initial meeting. We really want them to become great friends! Please help!

Answer
While stressful, this sounds like a normal ferret introduction.  I would suggest making sure the male is healthy (no adrenal disease), but it sounds perfectly normal.  Make sure they both have the same space so you need to stop separating them as this can make it worse.  Keep the cage open and make sure the female has a place she can hide.  We usually use a box of some kind with only one opening so she can get in it and defend the opening.  Be patient.  This can usually take a few days once they are together full time.