Rihanna wants to get `spanked` by Katy Perry

London: Rihanna has invited Katy Perry to spank her bottom when the friends get together next time. The 28-year-old popstar took to Twitter to quiz Rihanna on why she wasn`t invited to party with her when she was in Los Angeles at the weekend. "Ermm... I was in LA Saturday night... Should I be proud or offended I wasn`t invited?" the Sun quoted Katy as tweeting. But the 25-year-old Barbadian singer pointed out that she was in fact in Miami - not LA - when she was caught on camera throwing money at a stripper and slapping the exotic dancer`s bottom. However, she promised Russell Brand`s ex-wife that she`d make it up to her. Rihanna tweeted, "Errm I wasn`t! Lol! #miaminights Howeverrrrr ... I`ll still let you spank me!" ANI