The gemara in Yevamot 24b states that
One suspected of relations with a gentile woman and she subsequently converted, may not marry that woman, since this will strengthen the
suspicions against him. But if he did marry her, they, the judges of
the court, do not remove her from him, i.e., they do not require him
to divorce her.
The gemara a bit later ...
In context, this was a special directive from Rabbi Yehuda haNasi to his sons. It is unclear whether he actually said this, since his actual words were the cryptic "Do not sit on the bed of an Aramean woman", and this is one of several interpretations proffered by the anonymous narrative voice of the Talmud.
In context, it seems to be a matter of ...