Created by Wieden & Kennedy and narrated by Michael Buerk, the 60-second ad shows three Welshmen regaling the viewer with tales of surfing in Byron Bay, Australia.
The first in the series featured an apology to those receiving holiday snaps and Tweets from friends and family in sunny places.
As with the previous ad, this new work warns the viewer to expect plenty more snaps from Three customers abroad.
The ad broke over the weekend and has already attracted more than 100,000 YouTube views, continuing the viral trend started with the dancing pony and singing cat.
A second ad follows holiday spammers Dave and Sherri discussing their trip to the Grand Canyon, where they took 50 pictures at the same spot for the benefit of friends and family.
The ads showcase Three's overseas calls service and introduce two more countries (Spain and New Zealand) to the scheme. The media for the campaign is by Mindshare.
Tom Malleschitz, the director of marketing at Three, said: "Our campaign is inspired by a genuine insight into people’s behaviour while they’re on holiday. They love to brag!
"We’ve tapped into this and created an ad that prepares the UK for the onslaught of holiday spam generated by Three customers using their phones abroad at no extra cost.
"The campaign will drive awareness of this unique proposition and, now we have added Spain, even more of our customers will be bragging abroad to their heart’s content."
The ad will be supported by 30- and ten-second spots, as well as cinema, video-on-demand, press, social, radio, outdoor and digital out-of-home activity.