(based off that one alloplush comic)
Alastor would be groaning in his room, making loud, crackling, staticky radio effects. He would be holding the bridge of his nose tightly, groaning. Lucifer came in, and asked what the matter was. Alastor lied, and Lucifer had offered to pet him. Alastor would bow his head down, letting Lucifer pet and run his fingers through Alastor's deer ears. He would be letting out small, animalistic-sort of noises of pleasure. Moans and bleat and such.
As Alastor was sitting, and with his head bowed down, he looked at Lucifer's crotch that was near his own, as his legs were slightly parted, and his heart thumped as he made small chuckling moans, before putting his hand infront of his crotch; gripping the part of the chair infront of it.
He would then tightly grip Lucifer, and press his face against Lucifer's chest, making small moans and noises of happiness