Longer question.

To put some context:

In the series in general, Tailia (Tai) and Audrey, both young adults, are lesbians, more specifically: Tai is attracted to Audrey and always declared herself as gay since she was young. In Book 1, there are three scenes about Tai's sexuality that aren't major. The first two are about a badge Tai owns (which Audrey discovers and supports Tai (it's also a reference to a movie I really loved)) and the third is at the very end, where one of Tai's friends talks about her to Audrey and Audrey admitting that she does think Tai may be attracted to her. Audrey also quickly mentions that she does like her.

For Book 2, I'm planning on diving way deeper into this subject than Book 1 (which was just a huge introduction, to be honest). Talking about Tai's past, relationships and maybe a kiss. I just want to be 100% certain:

Do you have any tips on how to make their relation believable? Anything that could help, I don't want to mess it up on accident.

Book 2 is already pretty different from Book 1, as it focuses WAY MORE on the characters themselves rather than the story (really, the story gets important at around Page 60). It feels a lot more personal, and I want to take some risks to make them and the universe more believable (I did get feedback saying that one of the things B1 did right was making likeable and relatable/real characters). So yeah, that's mainly what I wanted to ask. (had to put a lot of context, but it's just to be sure, even if it does spoil a little bit)