It's a sniffling sound, so it could be the result of sadness or allergies. However, the phrase here is "guzu-guzu," which means "to dawdle/stall/beat around the bush," as the translation currently indicates.
Tomomin is that for real?Oh you helpless virgin~Now now, don't just keep it. Quickly hand it over~!Ummm, Yuina-chan... this... I wonder if you could pass this to your brother please?...Ehh??Wow!! That, could it be a love letter--!? Kyaa~♥