I think she just misunderstood that Hiryuu is dating with someone and too excited to type so she called her instead.
ReadHiryuu-sanHiryuu-sanHiryuu-san WellLet's seeHiryuu-sanHoushou-san!Does a pair of loversHiryuu-sanSorry if I bother you!Actually called an "Avec"!?Houshou-sanI don't understand a thing from your squealing...Hiryuu-sanReadReadHiryuu-san