Timing of investing using two SD accounts

[Shera Gregory]

My understanding is that it is permissable to have two self-directed accounts that would normally be prohibited from each other (for example my IRA and my spouse's IRA) as long as the funds are invested at the same time. So for example doing a private money loan using $75,000 from one account and $25,000 from the other could be done if the note were structured with those amounts. I believe this would mean that if in the future additional funds were needed for the loan it would NOT be permissable to add funds from a third account (for example, SD 401k) but that it would be OK to still add funds from the original accounts. In this example of adding further funds would that have to maintain the 75/25 split that was in the original investment?