The Movie cuts to the next scene, which shows Markus on his computer, writing on a pedophile forum. Markus voices concern about how he feels he might hurt Arthur.
Another member tells him “kids like it” (I guessing he’s referring to kids enjoying to do sexual acts with adults) or else they wouldn’t do it. Then he provides advice on how to treat kids (I’m guessing how to introduce a child to sexual interactions gradually) and provides a link. Markus declines. As we can clearly see Markus is not just interested in sex, he loves children. And that’s exactly what he tells the other user. The other user replies with a snappy remark about how he loves them all too. Markus becomes irritated by the person’s crude remarks. He leaves the forum.
Now the movie cuts to the indoor water park. Markus is with Arthur: they are playing together at the pool. I don’t understand anyone who doesn’t find this the cutest thing ever! Next Markus is seen taking pictures of Arthur. Markus tells Arthur it’s their little secret: don’t tell mom. Next they are in the public shower together. Markus really takes his time lathering the soap on Arthur’s body. Another guy in the shower catches him in the act and looks gravely concerned.