It would, of course, be a shock to wake up in someone's arms without knowing how you wound up there, but I'm happy that Lois processed the shock quickly, understands that neither one was to blame, and isn't reacting badly to Clark. Though she recently had a traumatic sexual encounter with Lex, she's not seeing this one with Clark the same way - that bodes well for the future. She believes him, trusts him, and still works well with him.
Since Clark understands what is happening to him, knowing that he's becoming under the influence of the red kryptonite, I hope he has the presence of mind to warn Lois - he can say that he feels the perfume from the shop is starting to affect him again and that she should go away so he doesn't do anything they might regret. On the other hand, though, Lois might not regret it.
Hi!
Well, for purposes of the fic, Lois did have to process everything quickly. Plus, she's Lois, so she'll focus any rage she has into finding/stopping Miranda. Plus, as you said, she knows and trusts Clark completely, so she's not going to react the same way she would with Lex, or Ralph, or even Jimmy.
Clark is too afraid of what's going on - treading on eggshells around Lois (given that he just learned about Red K and he slept with a woman who was only just sexually assaulted) - so he's going to stay quiet about the perfume affecting him. And he sees that Lois isn't being affected, so saying that it was getting to him would only raise questions he doesn't want to answer.
Although, like you pointed out, Lois might not regret if there was a repeat of last night.
