The 32-year-old was filmed squatting outside a bar in Los Angeles on Sunday afternoon, with a trickle of water issuing from beneath her skirt.
But Pressly, who became engaged to entertainment lawyer Simran Singh last Thursday, said she had completed a dare at her bridal shower. She wrote on her Twitter page: "Yes, that is me doing dare number eight at my bridal shower. Things are not always what they seem. Notice my hand in the back? It's pouring a bottle of water! C'mon guys! Do you think I would really pee in the entry way to the Abbey in broad daylight!"