Been looking for this Thriller from the mid to late 70s. What I can remember I think it’s Parents with a young blonde son, possibly has glasses on holiday, possibly in Texas. I remember the beginning of the movie had like a camper the family was in. There is a killer stalking the boy. Later they are in a hotel and the boy is being babysat by a very fat girl and is killed while watching TV and eating chips.  I caught this movie on A&E many many years ago.