Yeah this feels very forced lol. Ruriko clearly finds her annoying and only knew her for like a month. Well, i guess if it leads to Kurumi realizing her feelings then sure ┐(´ー`)┌
I agree with it being forced. What kind of person sees a "friend" and meets their spouse and so immediately plops their butt down at the table begs for them to buy them stuff. I know of people that are that rude, but not many. Even in Japan, no matter how polite and hospitable the people are, that behavior is grounds to tell them to bugger off.
Being essentially homeless, unemployed, and probably close to penniless mitigates that a great deal, I would expect.
Also, it's the spouse that invites them to sit at the table, she didn't invite herself.
She was about to leave too. She didn't force the situation at all, she was invited.
Rio is kinda rude but not particularly so, specially when dealing with a friend. Like, the only thing she asked was an iced tea, after being invited to sit in. Considering she had already told them she was homeless, I think it would be rude to not buy her something. It would just be awkward for her to sit on a table without consuming anything but she clearly didn't went into there with the intent of expending money, so paying her something minor (like a cup of tea) is only natural, I think.