Well it is a joke about a girl about to get married who told her guy she's a virgin even though she wasn't. In order to convince him she put some fresh liver in her vagina so it would feel tight and bloody. On the wedding night the couple had love all over the house, etc.
Next morning she finds a note that said "last night was wonderful but I don't think we are meant to be together!
PS..your vagina's in the sink"
Meaning at sometime the piece of liver fell out and the guy understood her game!!!.