Is sex special?

Is sex more special than other sexual acts? Is there something significant or profound inherent to sex that’s different from other sexual acts? What defines sex for you? Are there other sexual acts that you consider more intimate? Do you feel like you necessarily form a bond with people you have sex with? What about other kinds of physical contact?

I think for a long time sex seemed—in theory, if not in practice—pretty mechanical and biological to me, and lately I’m thinking otherwise, but not entirely sure why. So give me your perspectives. (Persextives?)