Iced water (well, water that used to have ice in it) in my cup.
I'll offer up my own little experience of moving back in with parents. We were moving to be nearer my parents, with two children (6 and 3) and one on the way. We intended staying for just six weeks over the summer, but our house purchase fell through, and we ended up staying for six months. It actually was a very pleasant time, for all of us I think.
It all depends on whether any party has unrealistic expectations.