Date: 6 Av 5599
From: Rabbi Moshe Sofer
To: Rabbi Shlomo
A young woman who became pregnant while serving in a locale with a non-Jewish majority sought to marry a Kohen, who offered to waive his priestly status. The Chasam Sofer firmly rejects the proposed sfek sfeika leniency on multiple grounds: priestly sanctity cannot be voluntarily relinquished, the majority of the local population is non-Jewish, and the father's Torah-credible denial of paternity undermines the first safek entirely. The woman is therefore forbidden to the Kohen.
Source: Shu"t Chasam Sofer EH II §124