User blog comment:Jopjopjop/Volume 18 Spoilers/@comment-16281343-20140619173248/@comment-1359322-20140620013428

If it was just between their group, the girls can still forcefully accept, but if it's an outsider, the girls clearly won't take it pleasantly. As you can remember in Volume 17, even Rias and Akeno can still get jealous with Rose, imagine if it's a woman of Gabriel's caliber, they sure as hell won't allow that.