src="http://t3.gstatic.com/images?q=tbn:ANd9GcTFNWYvNTqsD9ZTkoFZwiCKIx5gyNqJKSV9USyfx2jBAmB0jaZg">"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!"