You guys remember American Idol? For all of the mockery that the show gets, it has actually produced some pretty famous singers. Kelly Clarkson, Carrie Underwood, Chris Daughtry, Katharine McPhee, Phillip Phillips, along with many other singers who garnered varying degrees of success.
Tattoo artist Maxime Buchi at Sang Bleu London Tattoo did the tattoo on Lambert's side. It's of The Gay God, Antinous, which is very on-brand for Lambert, who has been famously outspoken about LGBT rights, and his own queer identity.
Lambert is no stranger to the tattoo parlor, and this likely won't be his last trip either. This particular tattoo seems like a perfect fit for the ever-popular (and successful) singer.