Help with Couples Counselling (Lumpinou's Relationships Mod)

As the title says, I need help with getting my sims to go to couples counselling. I've had one sim ask the other sim to go to counselling, booked a session on the computer, but they don't leave the lot. I thought they disappeared off-lot but it's not happening. Am I wrong on that? If not, what am I doing wrong? Any help would be appreciated.