The Robin Corporation is owned as follows:

Isabelle

26%

Peter, Isabelle’s husband

19%

Sonya, Isabelle’s mother

15%

Reggie, Isabelle’s father

25%

Quinn, an unrelated party

15%

Robin is on the accrual basis, and Isabelle and Peter are on the cash basis. Isabelle and Peter each loaned the Robin Corporation $40,000 out of their separate funds. On December 31, 2012, Robin accrued interest at 7% on both loans. The interest was paid on February 4, 2013. What is the tax treatment of this interest expense/income to Isabelle, Peter, and Robin?