How do we think about actssuch as fellatio, cunnilingus, anal penetrationthat seem clearly sexual yet may have other meanings?

How do we think about actssuch as fellatio, cunnilingus, anal penetrationthat seem clearly sexual yet may have other meanings? What do we make of actssuch as kissing, hugging, cuddlingthat may or may not be considered sex? These questions in turn raise a third: Are certain acts associated with specific forms of relationships?