i agree in parts to what most people have advised.
it does depend on the OP and whether she trusts to her DH. However, does she trust her DH's family?
i am sure the OP has no problems with the DH staying at home on her own. but it is the problem with having her family to stay as well.
there is a risk that one of them is the black sheep of the family... would he steal something? run illegal activities?
even if that is far fetched, having more people in the flat espcially some who don't know their way around and dont know how things like the cooker or washing machine etc work just raises the probability of a disaster.
there would probably be no problems at all. but if the OP came back and found that the flat had flooded or burnt down because one of the sons didnt turn off the cooker properly, she would be regetting it all her life. what can she do? fire the DH? make her pay back damages?