The first time it happened to me was when I was serving in Vietnam in the Marines, about 1970. I worked in the supply dept., so we had allot of tents full of equipment. I got to know one guy very well and I talked him into letting me give him a blow job. I was an expert at the casual seduction of a straight guy. I took my time to enjoy it and sucked his cock and his balls to get him to the edge. And then he shot a big load and I loved it. I swallowed down every pump of his cock and licked all the cum from his cock and balls. We made a habit of this every few nights. We would just go into an empty tent, so it was very easy. I loved sucking his cock and working on it slowly. Also would suck on his balls working up more of his cum. I asked him if he would like to fuck me in the ass and he said sure, so we found some sort of hand cream or something as a lubricant and I did it lying on my back. It hurt for a few pumps, but then it started to feel great. I had my legs up on his shoulders, so he got in deep and I could feel his balls slapping against my ass. I was also masturbating myself while he did it and he even took hold of me to continue my masturbation for the first time.
When he finally started cuming, I could feel it was warm. He then pulled it out and I grabbed it and worked the rest of his cum all over my stomach and chest. I shot my load then too all over both of us. It was a wonderful feeling. Then, I rubbed it all in and thanked him. He did it a few more times like that in the coming months. Until he was transferred. I think about it often while masturbating . . .