8. He can’t lie
This one isn’t so much about Steve but more about anyone who is in love with Diana Prince. But in the newly released scene, it is clear that Steve is willing to use the lasso of truth whenever Diana is in doubt.
In the scene in question, Diana learns that Steve lied to Ares in order to help him do his job. When she asks Steve “How do I know you’re not lying to me now?”, he grabs the lasso of truth and wraps up his hands.
For those who don’t know what the lasso means, basically anyone who is wrapped in the lasso of truth must then tell the truth. Pretty simple, right? Well, Steve finds himself in it quite a bit. But he’s always willing to use it to tell Diana the truth.
It’s an important part of their relationship because it proves that he is willing and able to be honest with her. He is a spy so it is in his nature to lie because it is his job but with Diana, it’s clear he doesn’t. He wants to tell her the truth and help her and that makes Steve an even better person. It would be so easy to lie to her to keep her safe but he doesn’t.