What does the phrase '我的妈来' mean when it is used to express shock or surprise?
I would say it could mean anything that could express surprise in English. eg, "Oh Mine" "Wow" etc. I don't think it means "WTF" and "Holy sht". it's just a surprise. it could be either bad thing or good thing that happens to someone. Usually, people would say "我的妈呀" or "妈呀" instead of "我的妈来" to express surprise.