I've never liked or agreed with people who speak badly about their partner with others. It's not only tacky, in my opinion, it's disrespectful. It's important to honor your partner in word, thought and deed. Again, if there is a real issue then seek professional help to get advice, not your friends or worse yet, your parents.
Disclaimer: I would assume you understand that I am not encouraging people to bury their heads in the sand and ignore or look over real issues. No way, no how! Real issues need to be addressed head on, and maybe even with the help of a professional counselor. But from my experience, many of the "issues" couples face are perspective and by making these simple adjustments in your own view of your partner will drastically change your relationship for the better.