Tank! What the hell, man?

Tank has reverted back to peeing and pooping in the house. He has decided going outside is not for him. This has recently developed since I got back from Utah. There were some instances where he would sneak upstairs to poop in James's closet, but that is nothing compared to what he's been doing the past few days. What usually happens is in the morning I will let him out and he'll go #1 and then come back in, get a treat, run around and then stand by the door again and go #2. This is because fat ass knows he'll get a treat every time he goes outside. Then throughout the day he'll stand by the door to go out or I'll decide he needs to go out. In the past 3 days he has gone #1 three times upstairs, one time in the kitchen while the door was open so he could go out, and has also gone #2 twice upstairs. I've yelled at him (a few expletives here and there) but now I'm so appalled all I can muster out is "Tank! What the hell man?". James told me this morning this is all my fault because I baby him. I asked for examples of situations where I baby him. All he could come up with is "You pick him up". Ok, I won't do that anymore, what else? "That's all I can think of". Oh, ok, so it's all my fault but you can't tell me why. Thanks asshole. So how do I get this SOB to start doing his business outside again?