I talk. It's hard sometimes, and might take some time for me to work up the courage to do it, but I've learned after enough times that it feels better after I've talked to my partners about it.
I love love love seeing the people I love happy, including when they are being made happy by others. I still definitely get jealous, though. I tell them so, but I also tell them that it doesn't mean I want them to stop being with the other people in their life. Some of my partners get confused by this, but by talking it out, we're usually able to work out some happy middle ground, where I get lots of "us time" that is very reassuring. And I get help in figuring out how to deal with my jealousy. I like help.
"Double standards" has a lot of negative connotations. I tend to just think of this more as "being human."