Rihanna - Rihanna Feeling Party Pressure

Rihanna feels "pressured" to throw an amazing bachelorette party for Katy Perry.

The 'Russian Roulette' singer has agreed to organise the all-female pre-wedding bash for her pal prior to her upcoming marriage to Russell Brand but says planning the event is taking up all her spare time.

She said: "It's taking up way more time than my tour! It's so much pressure. Her wedding is probably going to be the best wedding I've ever been to and now I have to match the bachelorette party to that."

Regardless of the theme she chooses for the party, the 21-year-old singer believes the bride-to-be will ensure it is a "wild" affair.

She added to US TV show 'Access Hollywood': "I could have balloons and Disney characters there and she'll still make it wild. That's just Katy Perry. There's no way around that with her."

Katy, 25, recently admitted she is concerned about what her friend has in store for her at the bash.

She said: "I'll probably end up s**t-faced in an alley wearing a penis hat."

The 'California Gurls' singer is expected to marry Russell, 35, later this year after the pair got engaged in December.