"Sounds great, right? There’s a catch. Soul mates only begin their existence as twins. Each soul lives their own lives and develops an affinity toward light or dark. While their destinies are inexorably intertwined, there’s no guarantee they’ll lie on the same side of the cosmic struggle when they meet.
Most importantly, soul mates whose affinity go in opposite direction become diametrically opposed to one another. To that end, there is only one way to get past such an antagonist – separate their soul from their body and send them back to the Akashic Records."
I wouldn't be worried about that. You can marry your significant other in game. The soulmates functionality doesn't seem to be one based on love like you are implying.
If your soul mate is a guy, you don't have to marry him or love him. You might even have to try and kill him. Though the same can ring true if your soul mate is of the opposite gender.