My gf's mother gets sloppy drunk and slobbers all over me. I've tried to tell my gf how this makes me feel but she just laughs it off and tells me to ignore it. I don't think I can do that. The woman has even tried to kiss me and my gf thinks it's funny. How do I handle this?
Your gf and family are in denial, AND they, including your gf, are enabling the woman's behavior by not confronting her. Unfortunately, the only way out if they continue to ignore the problem is to end your relationship. You may not be able to overcome family dynamics.