I had Samantha O. leave Peter and marry one of my sims. Once the babies were born I used SimPE to show my sim as the father (I consider it an adoption). They are children now and I've experience no glitches of any kind.
I don't think the boys are that ugly. My sim and Samantha O. just had an adorable baby girl also!
Liam and Ian Ottomas-Madrid:
http://img.photobucket.com/albums/v693/Nokomys/liam.jpghttp://img.photobucket.com/albums/v693/Nokomys/ian.jpgKylie Madrid (mom Samantha O. who is now a plant sim):
http://img.photobucket.com/albums/v693/Nokomys/kyliemadrid.jpgOh, do they live in Strangetown? She came home with my sims from work in one of my custom neighborhoods- I never play the premade ones.