No rudeness here. I said:
Well, ask yourself this. If they have no physical relationship, doesn't the whole "By the Sea" song seem a little strange. She's saying, you know what I'd like, lets move to the sea together, and get married. Is that something you say to someone you don't have a relationship with? Sorry. You're stretching. Its obvious their relationship is at the point where she can discuss marriage as an option. That doesn't happen in platonic relationships.
Are you really suggesting that in the song she's saying, "We can go to Brighton, then you can start bonking me and then we can get married. Alright love?". No way. The song assumes a relationship or it makes no sense.
You said:
She wants to get married. He doesn't even want to touch her.
Since that doesn't address any of the reasoning behind assuming marriage is on the cards with a platonic business partner I assumed you had missed my post. If, in fact, you just ignored those points, then the rudeness is not mine, but yours.
My argument is certainly not that only those who have sex want to get married and I can't see where I inferred that. My argument is that people who are not in any kind of relationship do not discuss marriage. Also, please remember that "By the Sea" is a duet, Sweeney continually reassures her with "Anything you say". Granted he is placating her, but it's a couple behaviour.
Your argument is that she wants marriage but he doesn't. Fine. Lots of people are in that situation. They don't tend to just assume it will happen and tell the other party that they will get married in a few years, after having had lots of sex.
You claim he shows no interest in her at all, even shrinking from her touch, yet you think its believable that she would assume he will marry her despite apparently rejecting her advances.
Sweeney does not like her showing affection, "the touchy" as you call it. Yet he allows her to speak of them getting married. And again, I say, the lyric explicitly states that they are sleeping together. The argument that this refers to some imaginary time in the future and not the here and now is a stretch, not the opposite.
Still, we all see what we want. Unless Depp and Bonham-Carter contradict it, I will assume they're playing the characters Sondheim wrote, who were lovers.