After having sex with my girlfriend i noticed my penis was dried and had white film.
So wash it!!!!
That white film could be her lubricant, or your semen, or a combination of both. Or perhaps it is a reminant of the extra lube that you two used.
I wouldn't worry too much about it, but it IS time to wash with soap and water down there. There are few things that smell worse that day-old spunk.
To the showers, my man...