I know exactly what you're talking about. Like in the Pilot when Angela says, "Well I'm not leaving Rickie here," Rayanne replies, "Rickie don't mind," and Rickie echoes softly, "I don't mind."
I think it has more to do with Rickie's initial insecurity than Rayanne and Angela's rudeness. Not to be a "blame the victim" kind of person, but Rickie LETS them treat him like that. He doesn't say, "Uhh, I don't like being ditched so you can run off with some older guys." In terms of general rudeness (with Angela and Rayanne interrupting him), he doesn't say, "HEY, I was talking" the way Angela does when Jordan kisses her. In general, younger people tend to be more egocentric (gaining a a world view is a mark of maturity) and hence they often interrupt each other and finish each other's sentences in order to have their own say.
Throughout the series, Rickie shows remarkable growth as he comes to terms with who he is. At the beginning, people frequently interrupt him when he speaks, and he is very non-confrontational. He sits on the fence about a lot of things. For example in Dancing in the Dark, he agrees with both Angela and Rayanne when they discuss the fantasy vs. the reality of Jordan.
Rickie : She's not saying that she...
Angela : I'm not saying...see there's thinking about him, right? Which is what I do. All the time. Like this...
Rickie : Obsession.
Rayanne : Right. So?
Angela : So, it keeps me going or something. Like I need it just to get through the day. It...It's just ...
Rickie : It's an obsession.
Angela : Right. And, and if you make it real, it's it's not the same. It's not, it's not yours anymore. I don't know, maybe I'd rather have the fantasy than even him.
Rickie : I completely understand this.
Rayanne : I totally and completely disagree. You want Jordan Catalano in actuality because...there is no because. You just want him. Only you're programmed to never admit it.
Rickie : That does have the ring of truth.
By the end of the series, Rickie has evolved and become stronger and more sure of himself. After Rayanne's terrible debut at Club Vertigo, he rips into her: "No! I can't anymore. You don't know how scared I was. I thought you were dead. I was picking out the clothes I should wear to your funeral." In Betrayal, he tells her, "Look I'm not gonna hang out here just to watch you get plastered!" and later tells a stammering Brian, "Hey, hey, Brian. Could you, like, pick a sentence and go with it?" Although he sympathizes with both Angela and Rayanne about The Betrayal, he tells Angela, "I'm on your side! It's like, impossible to be on Rayanne's side." In the series finale, he confronts Rayanne and accuses her of being unhappy. If you notice, he doesn't let people interrupt him anymore. Instead of simply responding and reacting, he takes the initiative and is assertive in conversation and in his actions.