Hmmm, I guess a few?
I think that B’arzz feels really guilty for taking advantage of M’gann’s pain, even if it really wasn’t him who used her. It takes a lot of affirmation from M’gann to convince him that there was nothing he could have done about it. But, then she can turn it around at times and say she should have moved past her fear to read his mind further, so she could have helped save him. To which B’arzz will tell her that she can’t think like that. They eventually accept that what has happened happened and move on from it.
In a romantic relationship, I feel they would really like going to the beach together, with or without Gar. M’gann loves the water and surfing and B’arzz likes reading on the sand and watching her enjoy herself, but M’gann doesn’t let him stay there for the whole trip! She (or Gar if he’s around) will drag him out to the water and make him play with a beach ball or boogeyboard and no matter how many times he’s seen it, he always gets flustered seeing M’gann in a wet bikini.
The beginning of their relationship would play out like a courtship because B’arzz is old-fashioned and really doesn’t want to pressure M’gann into things she isn’t ready for (which, if he read her mind, he would learn quickly that isn’t the case). However, even though she does want to quicken the pace at times, M’gann enjoys the steadiness, as her last two relationships were head-over-heels, instantly passionate affairs and with him, she can be grounded.
Lastly, (slightly nsfw headcanon because goddammit, I already want to write smut and I have never even considered writing smut with my other ships in YJ, but that may have to do with the fact that they’re older so I feel more comfortable writing it?), M’gann gives B’arzz permission to read her mind whenever they’re getting intimate, but he never does because he thoroughly enjoys exploring and learning for himself just where and when she wants to be touched.
Also, unrelated headcanon: Jaime’s nickname for GB is verde (green in Spanish).