Exene Cervenka is a writer, visual artist and punk rock pioneer. The OC transplant is the lead singer for X, the Knitters and Original Sinners. If you want to ask the legendary vocalist for advice, send an email to firstname.lastname@example.org.
You probably cannot repair your “friendship” with her, and please don't try. Apologize to her for the misunderstanding, explain you should have mentioned being in a relationship. Tell her that you like working with her and want to put it behind you. And never do this to another woman again. Then you won't be an asshole.