It could mean you feel insecure about your relationship.
It's about you, what's going on in your subconscious. There's no mysterious force giving us oblique glimpses in - let's face it - really indirect ways. So papadder may be right.
If you wake up with a hard-on it must of been a good dream. LOL
It means that you and her need to get it on. Take some pictures , Maybe some baby oil . Or jelly.