Older fic, Sex/Heat Cursed!Cas, mpreg, long fic

[greenerginger]

I cannot remember everything, especially not the title or details that I can search by,but I am looking for a long mpreg, mating curse type fic. It starts with Sam and Dean in a hotel room when Cas appears. Cas has been cursed by either another angel or a demon to breed. Touching him makes the guys go into a trance, I think.

Lots of sex happens and they all end up they all end up pregnant. Dean (?) gets taken by demons before he delivers and they use him to breed. Sam and Cas save him but he is changed. They all move in with Bobby and when Gabe visits he expands the house for them.

Thanks! Also, I apologize for any spelling grammar errors, my nook likes random Qs sometimes.