I truly do wish this was not the case, because it would be so much more easier for everyone collectively. However, if they are soul mates, and Seamus is already in a frenzy from trying to stay away when he has the pull, it is only going to get worse. It could mean the next time he is in Luka's presence in the future, he will want to rip him apart to consume him. If it is a soul mate bond, it is a very strong one.