As mentioned by others, pages 10-12 was a chant often done by otaku during concerts called Gachkoi Kojo (ガチ恋口上)
Chant goes:
言いたいことがあるんだよ
やっぱり◯◯はかわいいよ
すきすき大好きやっぱ好き
やっと見つけたお姫様
俺が生まれてきた理由
それは◯◯に出会うため
俺と一緒に人生歩もう
世界で一番愛してる
あーいーしーてーるー
Which translates basically how it went in those pages (with ○○ being a placeholder where you insert the name of who you're cheering for)
The chant ends with AISHITERU which as any good weeb knows means "I love you", so realistically no, this does not mean he romantically confessed to her. Considering his attitude, he still has yet to realize his feelings for her are romantic.