I read it some while ago and I can't even remember if it was an arc in a quick transmiration novel or if it was just one story (but I lean towards QT-novel). The MC transmigrated (or was reborn?) near his wedding to the originalML, who was in love with another person (originalMC i think). At the wedding the reborn originalMC appeard and crashed it. The MC said he didn't want to marry the originalML anyway and left with his family. I think the ML was the cousin of the originalML (but their family had some problems in the past and his father hated the cousins family). He also attended the wedding and fell in love with the MC. The MC and his family are some kind of wine making family and the MC is brewing new wines. I think the originalMC's family was also in that business. More to the original MC: In his past life he ran away with his boyfriend (not the originalML), who was a poor painter. They had children but lived their whole life in poverty. So when he was reborn, he left his boyfriend and his children and ran back to the originalML be rich again.
I found it!! It's the last arc of "turn on the love system". It is only translated to chapter 8 so I read it as MTL. It is with this third male gender that can get pregnant (somtimes called ger).