The 39-year-old actress wore a tight-fitting dress to the bash, but nearly suffered a huge embarrassment after going to the toilet when the full-length zip snapped.
Kate — who is married to businessman Ned Rocknroll — explained: ”I was at a 60th birthday party, feeling great, wearing a dress that could be unzipped from the bottom or the top. So my husband, Ned, puts me into the dress at home no problem, but when everyone started to move in to be seated for dinner I needed a wee, so I said to Ned, ‘Go on I’ll see you in there.’ I unzipped it from the bottom, sat down, had a wee — no problem — stood up, zipped it back up, and the zip came off in my hand. I stood there, knowing everyone is pretty far away and I can’t f***ing move. The dress opens all the way — the whole f***ing thing! I’m standing there in my knickers and heels, basically wearing a black cape!”
The Titanic star said the unfortunate incident has convinced her to avoid wearing zip-up dresses to any future red carpet events.
She told Vogue.co.uk: ”All I could do was stand there, look at myself in the mirror and crack up laughing. I am never getting on the red carpet in a dress with a zip.”