How can I appropriately handle a family member who frequently shows me his dick.?

The subject line is generally what he’s done but more specifically he frequently shows me his dick during showers we share. I’m in my mid 30s and he’s in his late 20s. We’ve been forced to share a bathroom with only one shower stall. I’ve put up with this for years and most the time give him the benefit of the doubt but it’s getting too weird. <br><br>He’s done this since we were kids but I assumed it was just a mistake or lack of self awareness but I’ve confronted him about this since we’ve been adults and he laughs it off. <br><br>This just happened to me again today. I opened the glass shower door and he’s standing there with his dick just hanging out. I confront him and he just laughs. It’s no big deal he says. I’m just barely containing my anger and tell him it’s not cool. He just keeps on laughing. <br><br>How am I supposed to deal with this? I’ve told other family members and they just laugh it off or think it’s weird. I’ve confronted this person multiple times. I just don’t know how to deal with this anymore.