When you're in the limelight, it's really hard to hide every single detail of your life.
These Asian and Hollywood celebs found out the hard way.
Everyone knew what they were doing last night when they were seen in public -- with hickies on their necks.
A 'hickey' is a love bite which looks like a bruise. It is caused by the kissing or sucking on the skin, usually on the neck or arm.
Check out the gallery below to see which celebs were 'up to no good'.