God created man and woman. Adam and Eve were the first created and when he created them he said to be fruitful and multiply.
Jesus said to "Love one another as I have loved you." Though, same sex partners are different from us in who they love. Jesus' words are to love one another. Therefore, shouldn't we accept those people for who they are?
As for what God says about same sex partners, I don't think anywhere in the Bible mentions anything about it. But remember why God had created this world in the first place. However, while reading HOOWANTSTONO's comment, I do agree with him in saying "God never created it so it's not part of his design." I agree with this because God is all knowing. He knows everything. He has our names written on his palm. He created this world and created us. He already knows what's going to happen and what has happened.
If you want to know God, I suggest to do what HOOWANTSTONO says and start reading the Bible for answers to your questions. If that doesn't help, then you can always ask a priest, a layperson, or any religious person who you trust.