The Voice coach, 39, and former Nashville Star finalist, 31, just announced their split on Monday "with heavy hearts" by saying "this is not the future we envisioned," however, the divorce papers were processed only hours later, TMZ reported.
Shelton reportedly secretly filed for divorce in Oklahoma two weeks ago. According to sources, Shelton was suspicious Lambert had been unfaithful to him on more than one occasion and he finally discovered she was cheating on him.
"Their busy schedules were a big issue for them... The less time they spent together, the more they grew apart," a source told E! News. "Trust was an issue for both of them. It went along with having to spend a lot of time apart. Rumors of infidelity put stress on them. Despite denials, even just rumors of cheating are still hard to hear."
Shelton and Lambert reportedly found it very easy to divide assets via their prenuptial agreement.
An insider toldUs Weekly that Lambert is getting the Nashville home and Shelton is walking away with the ranch they shared in Oklahoma. The 1200-acre property belonged to Shelton prior to the marriage.
The pair had a lot of animals together -- 15 of which had been rescued -- so that's a tricky situation when it comes to the split. The insider told Us that Shelton and Lambert are "working that out" although Lambert will likely keep most of the dogs. Each party will keep his or her own horses.
Lambert and Shelton's other pets reportedly include a flock of chickens, two pot bellied pigs and three cats.
The couple met in 2005 at a CMT event while Shelton was still married to his first wife, Kaynette Gern. Shelton divorced Gern in 2006, and he and Lambert reportedly began dating shortly thereafter. The country superstars, who have recorded hit singles together, wed in May 2011 after six years of dating.