I had to stop myself from putting commentary on all of the hilarious ones because I would have been at it all day. "and Giriko isn't sure what to do!" No, I suppose he wouldn't be. XD Marie and Arachne "stranded with no hope of survival." Arachne makes "Really. Is that so." face.
Both Giriko kink and mutual masturbation kink are perfectly good reasons. :3
My problem is that I really really like Stein and Marie's relationship in canon. The fact that she is desperate for a husband and he is her ~first love~ and they care about each other a lot and yet their relationship can be completely platonic makes me ridiculously happy. (Caring about friends who are important to you! It's awesome! Even between men and women, and even if there's no romantic/sexual element!) Same thing with Spirit and Marie, I think their friendship is adorable.
Which is a bit weird because usually I ship friends all the time. I guess I like it better platonic because it's breaking expectations?
And yet I am completely willing to write Medusa/Marie with snakes as insertion toys, apparently. This is news to me.