https://i.imgflip.com/7bz086.gif
Hmm, let's see.
1: It is unnatural. Nobody is born with both things, and if they are that is called a disformity.
2: It is unethical. Marriage is supposed to be 1 woman and 1 man.
3: It is an abomination to marriage. If you say "It's just for being together" then you can just be friends.