She never said it was prohibited, she was just stating that it wasn't recommended, its just allowed. On the other hand, It's sunnah mu'akadah to get married, since the Prophet (PBUH) said in a hadith that when you get married, you fulfill half your deen. When you get married its obviously to one person, you don't marry several people at one time, so that's the utmost part. THEN if the couple talk with each other and the husband wants to help another lady out, he can do so by marriage since thats the easiest (most lawful) way. But if the husband needs several other women to 'satisfy his sexual desires', then thats up to the couple, though I don't see why he would need to do so.