This past Christmas Eve I was drinking with my father-in-law. We had nearly finished off a full bottle of 25 year old scotch and decided not to go to the midnight service. Our wives decided to go anyway and left us alone. I'm not very clear on how it happened, but shortly after they left I was on my knees with his big thick cock in my mouth. He was skull-fucking me and I was gagging mightily on his hot cock. He was really getting off and just before I thought he was going to cum he pulled me up from my knees and led me into his man-cave in the basement. Once there we both stripped naked. He had me kneel on the edge of a big arm chair and produced a tube of lube. After greasing his cock and working some into my ass he proceeded to force his cock into me. I wouldn't say it was painful, but it was very uncomfortable at first. He took it slow and somehow worked his big tool balls deep into my ass. Too my amazement I became rock hard as he began slow powerful thrusts. I couldn't believe how much I was enjoying myself as he began to pound my ass in earnest. After a while his stokes became more intense as he put his full weight into it and finally shot his load in me. We emerged from the basement just as the women came home from church. I was shocked when my mother-in-law gave me a knowing wink. Christmas day I rode with him into town to get cigarettes and sucked him off as he drove. That's how I spent Christmas at the in-laws.