Pee EVERYWHERE

This week has been a week of testing my patience. William seems to be going backwards in the potty training world. He's been potty trained since February and he's been doing awesome, except recently. He has been peeing on the rugs, carpets, door mats, basically anything that can absorb pee, he's peed on it. I have no idea why William is acting out this way, but it is driving me and Chris up the wall. The other day he was in time out in his room and he peed under his bed. Then he peed next to his bed the following day. Yesterday I caught him peeing under his easel in his playroom. A week ago he peed on the rug in his playroom. After giving him a stern talking to and told him do not pee on the rugs, he peed on the floor next to the rug. A tad bit witty since technically he didn't pee on the rugs, but still unacceptable. I have no idea what his deal is, why he's doing this and why he thinks it's funny. My patience is running out...quickly.