I think this movie is from the 70s or 80s but I'm not sure. It's been years since I've seen it. I remember that it's about a little boy and his irresponsible mother. The scene I remember most vividly is how she performs Santa Baby complete with dance and costume for her boyfriend. It also could have been her neighbor, I'm not sure.
If you have any idea which movie that could be, please help me. :)