Is there any negative effects of biting? like sexual shoulder biting

Infection: The human mouth actually has more bacteria that dogs and cats....If you do bite make sure your mouth is as clean as possible. Also, be smart, don't break the skin!

Biting: Negative effects of biting include, but are not limited to, gross trauma and infections. If the biting is hard enough to damage tissues then scarring can occur/bones broken depending on location. The major concern is infection and spread of disease. If the skin is broken there are many strains of bacteria in the mouth that can cause infections of varying severity.

Sexual biting: If you like the sensation, then i wouldn't worry unless the biting is hard enough to leave marks or break the skin. Even hickies if done enough can discolor the skin permanently. If you draw blood, you can get infections or scars so be careful. Of course, be sure you trust your partner and that you both are free of sexually transmitted diseases because hepatitis could be transmitted this way.