I'm... very confused about the male lead's name. In previous chapters I noted his name was Shin, then in this chapter he introduces himself as Masato Oogami (prob. an alias?) and on the same page Ingrid calls him Makoto...
Me thinks Beowulf isn't so much jealous as he is concerned that some random schmuck she just met is now her fiance. Said random schmuck is the hero, but the point stands.
Still, it is funnier to imagine him jealous.