The Fashion Police co-host was all smiles as she held hands with Matthew while on the red carpet.
Kelly attracted attention in her vibrant floor-length gown, which featured a large bow at the back.
The 29-year-old styled her purple locks in a top knot, complete with a gold studded hair clip at the back. She completed her outfit with chunky gold earrings.
Meanwhile Matthew, who looked like a proud fiancé as he stood by Kelly, wore a smart black suit, with his long black hair loose.
The couple, who got engaged at December last year, were later seen sharing a private joke as they posed for photographers.
Despite appearing to look confident, it seems Kelly wasn't quite so keen on her red carpet pose.
Taking to Twitter this morning, she said: "I seriously need some lessons on how to pose on the red carpet! I always look like I am in pain or smelling s***!"
It was a star-studded event at the gala on Thursday night (12 December) to raise money for live saving AIDS research programmes.
Hollywood actresses Goldie Hawn and Zoe Saldana was in attendance, along with Vanessa Hudgens, who showed off her toned midriff in a cropped black jacket and maxi skirt.
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