Vol 3: Ch 147 – Overwhelmed
Rei already controls her laugh when she heard her family members talking inside when she knocks but then seeing Lyn's reactions now she can't control anymore and she explodes that cause her to laugh hard.
"Ha, ha, ha, ha my stomach hurts ha, ha, ha (and she wipes her tears by her right hand due to over laughing) I don't mean to scare all of you and I just want to give you a surprise but I never thought all of you would be like this especially you Lyn and your reactions is very priceless (then laughing again)"
The staffs are all surprised that this is their Ma'am Rei and the first time hearing her laugh like this.