There are a multitude of opinions that are popular in online social networks (OSNs). Typically, an opinion creator attempts to push his opinion to OSN users to gain the maximum possible benefit. In the situation that there are a conflicting pair of opinions, this article is devoted to developing a pair of opinion-pushing strategies that are acceptable to both of the two opinion creators. Based on a novel conflicting opinion propagation model, we model the original problem as a differential game-theoretic problem. By means of differential game theory, we derive a promising strategy-pair of the game-theoretic problem, accompanied with a few examples. Finally, we find that the promising strategy pair outperforms a large number of randomly generated strategy pairs in the sense of Nash equilibrium solution concept. Therefore, we recommend the two opinion-pushing strategies in the promising strategy pair to the two opinion creators, respectively. This article has potential applications in diverse areas such as misinformation restraint and competitive viral marketing.