Their kiss looks so fake or they are not even using lips, just pressing up against each other.
Imagine kissing in-front of millions of people, thousands if you just count the actual people there.
Then cameras are flashing like a child enthusiast at a children's crosswalk, and to top it off, you are now both going to be hounded by the media for the next few days.
Yeah, because that wouldn't induce nervousness/fake-kissing.