I've said it before on a different thread that I'm against me marrying a second wife out of their whims and for no good reason. But, that being said, a man does not have to ask permission from the first wife to marry another wife. That's unislamic. When my mum and dad were married, the bills mama had a clause where the groom could forgo his right to marry any other woman while he and my mum were still married. I think that's a good idea. But to have a man ask permission is against our religion. Imagine the Nabi of Allah PBUH asking one of his wives permission to marry another woman???
I'm a strong proponent of women's rights and raising their status in this misogynistic society. But what is unislamic should never be promoted.