Hm. Someone who feels this guilty just from sniffing hair never has the mental fortitude to go further.
Yeah, as I said it elsewhere about the last chapter, Hino seemed possibly even more nervous about this than Koguma after hearing they would be alone in the house. She clearly didn't expect that, and possibly only even suggested going there for the request to use it as an excuse to see Koguma's room.
Well, she may still go for something unexpectedly brave, though, being there together is clearly affecting her brain already. :D