Published Thursday, 27 September 2012
The British funnywoman was snapped cuddling up to the host in a park in Los Angeles earlier this month, and the pictures have been published in The Sun.
An onlooker tells the publication: "We were surprised to see them being so intimate. They looked very much into each other and had that besotted look in their eyes."
A source adds: "They're very happy together and love spending time with each other."
Tate, who has a daughter from a previous longterm relationship, has previously been linked to Take That star Jason Orange.