opinion? or options?

well i want to open both windows fully so i can really get the air in this house recycled, But i want teufel to enjoy the time with the windows open.
I cant shut him into a place and i dont want to shut him into one room because he is having a ball chattering to birds.
What do i do? Put him on his cat leash and tie it to the table so he can still watch at the window but cant get out? or dont even bother with the windows being opened?

It sounds like you need some window screen Fwan. That would be a good project for you and BF. Get a screen kit and make screens for at least two of the windows. Two makes it easier for air movement.

I vote for screening the windows. Tethering Teufel to a table leg may cause him to become injured. He could tangle himself up or leap for a bird. Being brought up short by the leash could hurt him.

Be sure to use heavy screen and secure them well. I've had cats go through flimsy screens.