[Mantis would like very much to believe Peter. She is just not sure that she does.

This feeling of skepticism is, overall, pretty new to her, and she isn't sure what to do with it besides make a face. She does feel somewhat reassured, or at least comforted that he seems to be kind enough not to make her feel any worse about what happened.

But she felt his heart, once, and she thinks sometimes Peter is too kind, and she does not want him to spare her feelings. ...Not when she feels already an endless sea of guilt that it took her so long as it did to finally stand up to Ego. Even knowing practically that without the other guardians he would have crushed her as easily as he did all the others. She should have done something.

But of course, she does not say any of that. Instead, she tries and fails to give Peter a small smile (she is not very good at lying, even on her face).]

If you are sure... [Peter might think she is done, but she is not. Sorry.]

But I wanted to say sorry. I feel... bad. I made very bad choices. I wanted you to know that I know that I did, and that it is okay if you wish you talk about it. It is also okay if you wish to yell at me...

[She has noticed sometimes it makes people feel better to shout at things.]