She's got to keep her pretty face. 

If that's what she worries about, whatever.

It helps for convincing people she's trustworthy. 

Yeah, she must need all the help she can get with that.

There's a pretty big gap between the reality and the lie. 

Yeah. There is.

She's not sure if she's supposed to be complimented or insulted, here. 

Whatever helps her sleep at night.

She'll pick 'complimented,' then. 

(2B is fairly sure Ash intended the other.)

(But teasing Ash is so much fun.)

(Well. As long as she's entertained.)

(She could tease 2B instead, if 2B wanted.)

2B is unclear why she might want that.

Teasing can be a way to strengthen bonds within a team, allowing them to gain an understanding of the other without necessarily committing to revealing too much of themselves. And stronger bonds and greater understanding of each other translate fairly clearly into success on operations, at least for her and Ash's species.

Surely then it would be better for it to be an 'as well' rather than 'instead'.

Unless 2B likes a different kind of teasing, or wants to get closer to Gamora specifically...

What sorts of teasing are available?

A wide variety, depending on their mood. And how many other people are in the room; Gamora's a private kind of girl, you know. 

Now she's curious, what could privacy have to do with strengthening the bonds of a team? Surely more participants would be desirable rather than fewer.

Is 2B not much for privacy, then? More prefers showing off? 

If that is what's called for.

"2B..."

"Yes, 9S? Do you wish to join in the bonding exercise?"

9S groans and buries her face in her hands. "I don't think that's what you're talking about anymore!"