No, pleasure is not a sin, it depends on what type of "pleasure" your talking about. Having sex then yes it is a sin outside of marriage. But God wants us to be happy, but not the world's kind. If you wouldn't want to tell your parents, or wouldn't do it if Jesus were watching you (which he always is) then don't do it. Answer:
Pleasure is not a sin unless, you are having pleasure with a married man or woman and they aren't married to you. All forms of fornication outside marraige are traditionally prohibhited. There have been civilizations in the past which have said yes to sex outside marraige such as the Roman and before that the Babylonian civilization and have corroded from within and we see their ruins before us. Whereas civilizations/relegions that have prescribed sexual discipline have survived to this day such as Hinduism,Christianity, Bhuddism, Islam and Judaism.