Hmmm, the one I can think of is the father wants to have a child with his wife and wants a boy. Truthfully, it will be much simpler for me if I don't fulfil that wish, as I already have plenty of Sims in the house already. I would be glad of an excuse, since I have been holding onto that wish for so long.
Do you think it would work to just move out the glitched Sim? Or does it have to be the whole household?