Oof, that reminds me that Reisen x Kaguya would end up with Kaguya outliving Reisen à la Keine and Mokou. Unless of course Eirin does something to Reisen to extend her lifespan, which is certainly possible.
The "spying on friends to see when they finally get together" trope is always amusing. Aya better hope that camera doesn't have too loud of a shutter click though.
Also it doesn't help that Anna is complaining when she's being such a messy eater. Plus arousing Elsa isn't gonna help get the blood out any easier... Elsa needs to be relaxed for the blood to be able to flow out better. Dammit Anna you idiot.