We study a DeGroot-like opinion dynamics model in which agents may oppose other agents. As an underlying motivation, in our setup, agents want to adjust their opinions to match those of the agents they follow (their 'ingroup' or those they trust) and, in addition, they want to adjust their opinions to match the 'inverse' of those of the agents they oppose (their 'outgroup' or those they distrust). Our paradigm can account for a variety of phenomena such as consensus, neutrality, disagreement, and (functional) polarization, depending upon network (multigraph) structures and specifications of deviation functions, as we demonstrate, both analytically and by means of simple simulations. Psychologically and socio-economically, we interpret opposition as arising either from rebels; countercultures; rejection of the norms and values of disliked others, as 'negative referents'; or, simply, distrust.