I'll spell out the ethics here, more for more own self-satisfaction than anything else:
Imagine you are serving a master (perhaps as a servant). If he's dissatisfied with you, he can kick you out to street, where you'd have to live in a Walmart shopping cart. Normally, do you want a dude to ram you hard in the buthole? Must dudes would say no. However if this master asked you to bed, with the implication that he wanted to ram you... Would you say no? If so, I would hope you have a particular love of either Walmart or shopping carts.
That's kinda the situation here. If asked, Liz can't really say no, no matter her personal thoughts or feelings. Which is why Shingo is hesitant to make any moves, both towards Chloe or towards Liz.
Is it a modern view of the situation? Yes, but Shingo is an adult man from the modern world, and not a person from the medieval times