Bringing another in

Is it wrong of me to want to bring another woman into my relationship for my SO, not like a 3 some (although I would love to bring up the courage to ask another woman for one) but as a partner , a best friend I can come home to and who could help me please him and do for him so I never have to worry about him sleeping with anyone else cause he has US , our relationship is great he says he loves everything about me as a whole and he hasn't cheated or anything but sometimes I feel like another woman would be great for us , we would always have someone else to depend on and please as well keep our lives exciting . Besides I want a huge family so that just makes room for more babies two wombs working thier Magic 😁 does this make me a bad person or wrong for thinking this way 😔 I would like an honest option .