This strategy would be considered a prohibited transaction. While at first it appears to be legitmate, the "indirect" reciprocal lending of money constitutes a prohibited transaction, as you are indirectly benefitting. Note: I'm not a tax attorney or CPA.
USC Title 26, Subtitle D, Chapter 43, 4975
(c) Prohibited transaction
(1) General rule
For purposes of this section, the term “prohibited transaction†means any direct or indirect—
(A) sale or exchange, or leasing, of any property between a plan and a disqualified person;
(B) lending of money or other extension of credit between a plan and a disqualified person;
(C) furnishing of goods, services, or facilities between a plan and a disqualified person;
(D) transfer to, or use by or for the benefit of, a disqualified person of the income or assets of a plan;
(E) act by a disqualified person who is a fiduciary whereby he deals with the income or assets of a plan in his own interests or for his own account; or
(F) receipt of any consideration for his own personal account by any disqualified person who is a fiduciary from any party dealing with the plan in connection with a transaction involving the income or assets of the plan.