How can cartoons be sexually arosing???!!!!?

The other day I was at this kids house I had to do a school project with. So I was in his room and he said i could use his computer to look stuff up for the project. I saw that he had a file on his desktop and when I opened it it was nude pics of mlp characters!!! I cringed so hard. I never said anything to him, but after i went home, I was really grossed out. How the fück can that be sexy? Like I understand that some people are gay, straight, and bi, but atleast all of those people are attracted to humans!