If you "consider it is re-investment",

In term of accounting, how do you explain the "extra 100K cash" in your book?
Is that for equity? That is not the case, your share stays at 80%.
Then it could only be a loan, which doesn't make sense.
When you reached the deal, you were not thinking clearly.

If you didn't pocket any money, from company account to your personal account, then intuitively it's a dilution.
In this case, your new partner invested 10W for 20% (afterwards) share.
Your original cost is 10W. Your stake after the transaction is 80%.
The book after the transaction has 100K extra working capital, together with other assets/liabilities.

If you are still confused, go talk to a CPA.