Electric Cardiogram? You mean an Electrocardiogram?
Now about the actual chapter, Legosi's advice should probably be:
"Step one: don't eat Louis' foot;
Step two: go ask grandpa because he actually succeeded in doing it"
@Harvester Never? Correct me if I'm wrong but we've only sort of heard of a fiance in passing. That was why Louis and Haru couldn't actually be truly together or at the very least was the excuse Louis was making very early on. Louis's dad may have mentioned a fiance too but yeah that's about it.