Going through some comics I ran into Steve Engleheart's run on Green Lantern that had Hal & Arisa (underage alien) get together after she unwittingly had her ring turn her into an adult mentally & physically. Hal struggles with it for a bit but eventually fucks her a couple of times. This seemed pretty pedo to me.
Another icky moment would be the whole Wanda, Vision & Wonderman triangle where the Vision basically gets rebooted into a emotionaless robot. Wanda asks Wonderman for his memory patterns to help get her husband back and Wonderman refuses because he loves Wanda. Previous to this story it had been established that these guys where not just friends but thought of each other as brothers. So it's a pretty big betrayal on Wondy's part. We also find out Wanda's kids were not real after all. The Vision has no penis. Wanda goes nuts. I liked these characters prior to this but ick! This may have been the first flop Byrne had with a team.
Anybody else have some icky moments to share for this icky topic?