I'm not reading Nisekoi's light novel/manga, so I wonder, how much of the manga does the anime's second season cover? Because I found that only a few episodes contribute to the story itself and almost half of the entire season appeared to be fillers. Is it also the same in the manga?
The first episode of season 2 starts at 51 chapter of manga and the last episode ends at chapter 106, but there was one filler episode (6th or 7th) with something like Madoka (I closed it right after I saw what's there). Also some chapters from this interval were covered in OVAs.
I haven't been reading the Nisekoi manga either, but I have seen this chart, which purports to provide a correspondence between manga chapters and anime episodes:
Assuming this chart is accurate, Mihai Svet's answer is roughly correct, though there appear to be a number of omitted chapters (above and beyond those relegated to the OVAs).
Season 2 roughly covers upto 105 or 106 chapters. There are total off 200+ chapters. You should start reading the manga. I too waited in the hope that More season will arrive. But its not arriving sad.