Women can be very competative with each other, and I do think you hit the nail on the head, that they may be vying for position in the family. Give it some time. You and your brother might want to plan some outings with your fiances so they have a chance to get to know each other. They may come around and become friends. Hopefully they will, because if they don't, they may both put you and your brother in the position of having to choose between them and your family. It's important to a woman to feel like she's the number one priority in her man's life, but these two seem to have gotten into a pattern of one-upsmanship, and that's not good. You can't really put anyone above your wife, so you need to let them know now that it wouldn't be right for them to put you in that position. Yikes. I really don't eny you and your brother. Good luck.