I had initiated a conversation about something I didn’t like being said to me and then the other person started talking about what they didn’t like about something I said to them a long time ago (but had never told me), skipping right over what I wanted to talk to them about.

I said to them:  Hey, I’m #1 here.  You’re coming in as a #2 but you’re a #1 too.  If you have something to bring up, initiate a conversation about that topic (at that time) and be the #1 that you are.  Otherwise, when you come in as a #2, you make me a #2 and I’m a #1 who doesn’t like going around and around in circles.  And at the very least, address and acknowledge what I’m talking about, come to a resolution with me and then we can talk about your stuff. 

If you have something to say, say it first.  Don’t wait for the other person to open the door and follow in behind them.  That’s not fair, empowering, or helpful.

Remember that you’re #1 and so are they.