My 35-Year-Old Sister Is Dating a 19-Year-Old, and I Can’t Even Look at Her the Same… Am I Overreacting?

I really need some outside perspective because I feel like I’m losing my mind over this.

A little backstory: My sister (35) has an 8-year-old daughter with a man who, from the start, our whole family knew was bad news. That relationship ended in flames, and during the breakup, she gained a following in the online “gun community” while also cheating on her husband with a guy across the country. She rushed into an engagement with him, even got a tattoo of his state, and—shocker—that also ended disastrously. My brother and I (we’re really close) were left picking up the pieces because my sister is wildly emotional and doesn’t handle breakups well.

Fast forward to now: She’s been into online dating for about a year, and some of the men have been noticeably younger than her, which has already been hard for me and my brother to watch. She was dating a 26-year-old for a bit, and even that felt weird, but now… she’s seriously involved with a 19-year-old. A guy who just turned 19 in December.

To put it in perspective, I’m 10 years younger than my sister, and he is 6 years younger than me. He is closer in age to her daughter than he is to her. And I just can’t get over how weird and wrong this feels. It gives me the massive ick. Like… what does a 35-year-old even have in common with someone who just graduated high school?? Not to mention, there is no way a 19-year-old can be a proper step-parent to her daughter.

She knows it’s weird, too, because she’s lied about his age to people. That alone tells me even she feels some level of shame about it. I just hate that she’s not thinking about her daughter right now. And honestly, I don’t even know how to talk to her anymore because I can’t pretend I’m okay with this.

Am I just being judgmental, or is this as weird as it feels? And how do I even handle this? Because right now, I feel like distancing myself from her completely.