On one hand, I’m really glad Sam didn’t get the Mark because I love him and I also didn’t want a rehash of seasons 9 & 10 only with Sam instead of Dean…

But on the other hand? Sam is so sexy when he gets all dark. Like…

?

??

???

????

?????

??????

whY AM I So SWEAty RIGHT NOw???

I think Dean agreed to let Sam take on the Mark because he wanted to respect Sam’s decision. Having said that, I 100% guarantee you that Dean assumed he could somehow save Sam before the Mark seriously affected him. Because “we can fix this” is an essential part of the Winchester DNA.