Ah Familiar Unhealthy Family Dynamics

So, I called my aunt yesterday while waiting to pick up my sister and her family from the airport. My aunt was surprisingly civil, and we talked about stuff. In thinking about whether or not to call her though, I realized that I do harbor some anger and animosity towards her because growing up, I always understood our relationship as such that she was this really important figure in my life who would always be there for me, and now she seems to care so little about me, having several times really taken advantage of me.

Then, my sister had asked me to babysit this morning, and she drops off my niece at 9am for what she said would be 2 hours (an excuse I guess just not to give me her booster seat so I could take her out - like to my mom's), but ended up being closer to ALL DAY. They finally show up around 3:30pm because Grandma's car broke down somewhere close by, and my brother in law is yelling and being obnoxious, and no one is telling me what's going on.

Finally, we all go out to dinner at 5:30 (because my dad offers to take us). Who ends up being at the table next to us, but my aunt. Yes, the same aunt. And she and my dad don't speak to each other at all. It was lovely really.

So, I'm drinking a little bit; I admit. At some point, Dad says, how unlucky that we end up coming out and she's here. I say: Well, at least you could be civil to each other. If I can put up with this guy over here(I look at my brother in law), you should be able to do it with her. Apparently, my sister indicated later, he heard me and is insulted.

So do I have to apologize? Or that he is a border line verbally abusive guy in front of me, does that excuse my comment?