Register partnership for same- in Sweden?

Hello. Will it possible for us as a gay partner to be registered in Sweden? My future partner is having dual citizen; a Swedish and Nigerian citizen. I'm Malaysian. Both of us are staying outside Europe. My partner is currently staying in Nigeria while I'm staying in Malaysia. We are planning to move to Sweden this year and stay close to his mum. His mum is Swedish citizen. My future partner both parent are a Nigerian (partner's dad) and Swedish citizen (partner's mum). Please help us, so we won't separate anymore because we're in relationship for almost 2 years. Besides that my partner want to be close to his mum after 8 years staying alone in Nigeria after his dad ped away. Now his mum married with another guy in Europe. Thanks...