I would suggest that you don't go along with the lie, if it's going to cause all this stress.

I don't know where your bf works, but I think it's easier to call in sick than to make up all this bs. It's kinda elaborate just to get some time off, I mean if he's in retail or food service then I can understand that this time of year is hard to get off, but is all that necessary?

I don't have a problem with lying, but I don't really like to use the excuse of sick/dead relatives, it gives me the feeling of pissing all over karma or something.