The phrase "lets next to" doesn't have a clear antonym as it is not a commonly used phrase or idiom with a specific meaning. However, the word "let" has several antonyms such as prevent, prohibit, stop, and hinder. These words mean to restrain or hold back something or someone from proceeding. The phrase "next to" can be contrasted with its antonyms like far from, distant from, or apart from, which mean a significant distance. In contrast, "next to" suggests proximity or closeness. Overall, while the phrase "lets next to" may not have a direct antonym, it can be understood by examining each of its components' opposite meanings.