Rape and incest tags added, on account of the title of the comic is literally "Sister Rape," and Nelson is clearly not enjoying what is going on here.

The_Monk said:

Rape and incest tags added, on account of the title of the comic is literally "Sister Rape," and Nelson is clearly not enjoying what is going on here.

Unfortunately, this site does not allow the use of the "incest" tag when talking about shipgirl sisters. This was already discussed with Kantai Collection.

EDIT: Apparently... that changed about a month ago...