Only half open…

So my wife has a man she engages with pretty frequently, we were both going to be open but I decided it really wasn’t for me. I don’t mind that she is, in fact it’s spiced our lives up a lot. It actually turns me on knowing when she’s with her guy. When she comes home I like having sex with her again, she tastes different after him, I love it. My concern is what if down the road I start feeling left out, like a third wheel?