Rihanna violated karaoke etiquette at a bar in Germany this weekend -- hogging the mic to yell and sing her way through TWO songs in a row but it's Rihanna so no one complained.
It all went down at the Thai Royal Bar in Cologne ... where a baseball cap-sportin' Rihanna and a friend sang "Don't Speak" by No Doubt ... followed by "Sex on Fire" by Kings of Leon.
A witness says: "She had just ordered some drinks and fries for the table then just decided to get up and sing.
"It was nice to see her having a lot of fun and she was clearly enjoying herself on her time off."
.webp)
