Should we take a loan from family members?

My husband and I make a decent income (over 75k a year) but we cannot afford for me to stay home with our 4 month-old daughter and make our house payment and student loan payments (the only debt we have). My Grandparents, who are wealthy, have recently offered to pay off one of my husbands two student loans in order for me to be able to stay home or pay of other things quicker. They expect for this to be a "loan" with no interest and no mimmum payment. In otherwords, we can pay them back when we can and if we can. They did a similar thing for my sister's graduate education. My husband refuses to accept this, saying it would make things uncomfortable. Is he right? Should I ask him to reconsider his decision? I don't want to put a rift between us but I desperately want to be a stay-at-home mom!