According to a traditional conception, romantic love is both constant - if someone loves another, they continue to love them - and exclusive - if someone loves another, they love only the other. In this paper, we argue that the essentiality of constancy and exclusivity is incompatible with the possibilities of fission - roughly speaking, of one person becoming two - and fusion - roughly speaking, of two people becoming one. Moreover, if fission or fusion are possible, then constancy and (...) exclusivity are obligatory features of love only if there are moral dilemmas. We conclude by suggesting this casts doubt on the constancy and especially the exclusivity of love. (shrink)