Guys come on .. by this point don't you trust the author? HE NEVER did any weird annoying creepy shit to any of the main girls or the MC and they went through A LOT! So I'm pretty sure Yuzuhira is a virgin, she looks like she's gonna join the MC and become one of his women so she's probably good. Author is literally on a mission to satisfy us with peace of mind.
Also Iroha will probably only gain some kind of power from being kidnapped or nothing will happen to her at all.. remember there's a reason why it was girls who kidnapped her. Like do you think we would be fine with a bunch of dudes kidnapping Iroha? Author knows what he's doing.