Advice about what? You didn't see her until you finished, because she wanted to see you finish. She was spying you while you jerked off, just like you would have done to her...I bet her twat was a sopping wet mess, and I guarantee you when she went back to her apartment, she had her hands in her panties before her ass hit the bed. All you have to do is laugh it off, and let her know you had no choice, because you didn't want to go elsewhere for the pussy you should be getting from her. Oh, and make sure she knows, next time you're gonna rub one out, you would much rather watch her do the same.