I really don't want to lie to them about it either but I just don't think I want to tell them right now. I think though if I don't go this time then they might really think something is up. I haven't even really told my own mom yet (she knows a bit but not all, I don't want to worry her) so how can I tell my fiancee's parents?
It just so happens that whenever we've gone to visit them I've had the flu, a cold, etc. They have dogs as well so my allergies get really bad when I go over there.