Relationship? What relationship? Kal doesn't even know his real name!
Lois has to stop this right now. There's no way she can move their relationship up/over/down/around several levels while Kal is suffering from amnesia. It doesn't matter that he's no longer carrying the weight of memory from Krypton. What will happen to this idyllic coupling when remembrance of things past returns? It doesn't matter that he has some basic attraction to Lois or that Lois has a very strong attraction to him. This isn't right!
I know, I'm not being romantic, but if she tricks him into bed with her (and that's how he'll see it when he remembers everything), how will he be able to trust her now that she's taken advantage of a man bereft of his past? And was he so unattractive to her when he had his memory?
What would Kal think of human romance and interpersonal relationships after having sex with Lois? "Wow, is this what I missed with Mayson? Let me call her now!" Or might he think, "Eww, this is really gross! How can humans possibly participate in such demeaning activities? I'll never touch a human woman again unless I'm saving her life!"
The mores and customs of Krypton are different from those of Metropolis, and whether or not they're inherently better, they're not what Kal is used to! If Lois wants to drive him far, far away from her, then she'll keep doing what she's doing now. But if she wants to gain his respect, she'll push away and let him know that while she'd love to get physical with him, it wouldn't be right. He'll appreciate that when his memory returns.
And he still has to take care of that last big fragment, doesn't he? Can't very well do that while he's in bed with Lois.
