Being rude or just minding my own business?

Why not just say what you want to say? “I’m happy for you two and I don’t want to be involved anymore.” That would clear the air and let you all know where you stand with each other. Otherwise your behavior—although perfectly natural and understandable in this situation—might be misinterpreted as rude, yes.

Since they don’t know your true feelings, it may come across as rude, despite you only wishing the best for them. If you don’t want to tell them why you are this way around them, then they can only come to a conclusion based on what they know. It’s up to you to set things straight, or wait for the relationship to fall to the wayside.

They may take your actions as jealousy if you are not careful.

Personally, I don’t think you’re being intentionally rude or minding your own business. It sounds more like you feel awkward around them and possibly even tongue-tied.

Put yourself in their positions, how would you feel about someone treating you this way? Your answer to that question is the answer to your original question!

You are not the first person in the world to feel this way. Read this question from someone feeling similar thoughts. Ypou will see the similarities.

If I saw them, I would stand tall, shoulders back, smile, and talk with them. Be friendly. – even though your heart is breaking. Talk about some subject you have in common: plans for holiday, school, college, job… Ask questions. Just be there. Smile and pretend it does not hurt.

Welcome to Fluther. I’m sorry you are here under such difficult circumstances for you.

You are being rude and your jealousy is very apparent.

You should acknowledge them by speaking if you know them.

You don’t have to engage in a long conversation.

Yes, you are being rude, and your behavior reflects poorly on you. Be pleasant and say hello, you don’t need to be in a long conversation.

This behavior means that if they do break up, she still won’t go out with you, because of the way you are reacting.