No way this fucker asked her seriously to take a shower with him, using "we're a couple" to take her captive. Still though, I'm not sure what she thinks of the proposal. Either she lo-key wants to do it, or she thinks he's still rushing a bit, and shes not mentally ready to bear it all (even though he has seen her partially nude before at the hot spring).
Oh and I can say without a doubt that if she agrees, she will be in a swimsuit, comeon Ichitaka, you gotta have seen that coming. She's by no means ready to show u her naked body.