The phrase "acted as if" implies that someone is not being genuine or sincere in their actions or behavior. To find antonyms for this phrase, we can look for words that convey authenticity, honesty, and transparency. Some antonyms for acting as if include: genuine, honest, sincere, authentic, truthful, transparent, candid, forthright, and open. These words describe behaviors that are not fake or deceptive, but instead come from a place of honesty and integrity. Using these antonyms in our language can help us communicate more clearly and effectively, and can lead to stronger, more trusting relationships with others.