It could even be argued that he thought he was doing her a favour, because forgetting her experience with him sort of helped her to move on; otherwise she would have been pining for him constantly. By causing her to forget, he was sparing her that pain, and at the same time condemning himself to bear the burden of that pain alone.
Jude, what pain was Superman condemning himself to bear in Superman II? To me, the most painful thing about the entire movie was how extremely pleased Superman seemed to be at having wiped Lois's mind after having sex with her. That smirk on Christopher Reeve's face at the end of that movie told me that his Superman was as happy as could be that he had gotten away with sleeping with her without ever letting her know about it. Talk about using a woman! Talk about pulling the wool over her eyes! Talk about lying about yourself to her! I found him utterly disgusting.
Anyway, if we agree that he was justified in taking away her memory of their lovemaking, I also think we must accept that he can never make love to her again:
Remember that since he had got his powers back, he could no longer be with her, and he had chosen his responsibility to humanity over his love for her
FoLCs, how will you feel about Superman if this is what the sequel to SR is going to tell us? Superman really has to make a choice between loving Lois and helping humanity? Forget the thoughts of Superman ever marrying Lois, forget the thoughts of a super romance, because Superman can't make love to a mere mortal without hurting or killing her. Forget about the marriage in the comics, and, not least, forget about LNC:TNAOS. If Superman can't make love to Lois, he can never be more than a simple crime fighter or an aloof guardian of society. Perhaps, at best, he can be a distant, Jor-El sort of father to his son.
In my opinion, Superman II is the worst thing that ever happened to Superman, because it did its very, very best to ruin every future possibility of a relationship between Lois and Clark. I'm so glad that this new movie tells us that Superman was entirely wrong to think that he could just mindwipe away the consequences of his making love to Lois. But if the next movie tells us that he really can't ever be with Lois any more, well... then I'm going to wish that "Superman Returns" does so badly at the box office that there will never be a sequel to it!
Ann
