Volume 3 of the Japanese tankobon is expected to cover chapters 13 through 18. If WeloveManga feels risky, buying the digital volume on Bookwalker Japan supports the author and gives you legal access to the raw of Chapter 16 within that volume.
Without specific details about the chapter, we can infer that the story might be building up to a more intense or dramatic moment, given the nature of manga storytelling. The title "Tsutte Tabetai Gal Sawa-san" roughly translates to "I Want to Eat a Gal's Sweets", which suggests a lighthearted yet possibly flirtatious tone. TSUTTE TABETAI GAL SAWA-SAN chap 16 Raw Manga - WeloveManga
If you're unable to access TSUTTE TABETAI GAL SAWA-SAN chap 16 on WeloveManga, you can try alternative platforms such as: Volume 3 of the Japanese tankobon is expected