User blog comment:B214/Volume 17 spoilers./@comment-117.193.172.96-20140220163805/@comment-1359322-20140221011013

As long as it's someone you know, you need to invite them into your house. Plus Issei constantly visit either one of the M&M's house, rejecting them would make Issei's family look selfish and arrogant. Not something admirable that you want people too think of you as.