Mariner is definitely down for anything. She’s dating the andorian Jennifer in a few episodes and she also went on a date with Steve Levy the conspiracy guy. She also dated an Anabaj to annoy her mom so…yeah.
She even says this in one episode (the Tom Paris one):
“Oh I’m always dating bad boys, bad girls, bad gender non-binary babes, ruthless alien masterminds, and bad Bynars.”