Why did he stop calling?

I met a guy last week it was a business meeting and we wound up sleeping together (the alcohol). Anyway I liked it so about two days later we did it again and then again. We did it four times and now the guy just stopped texting me to hook up. Just before this I got a little pissy with him for hitting on my friend right in front of me but I got over it and slept with him again that night. I didn't really care because again I wasn't trying to date him just wanted some good . Why would a man let go of good easy , he d everytime in approximately 5 minutes tops, so it couldn't have been that bad right...