legal virginity

The status of someone's not having a criminal record.

There is hardly any policeman --- no matter how big an a**h**e he happens to be --- who wants to be seen as "da big bad guy" who "took someone's legal virginity" over a comparatively minor event, so if you have a clean record "thus far", are always respectful to Johnny :Law, and try to behave yourself as best you can, you stand a much better chance of staying out of legal trouble, even if you accidentally "screw up" once in a while.