my headcanon is that Rodion has always been like "I may be a little bi" but never ever tried with a woman until joining the bus.
in part because she fears feeling envious of other women, in part because men are easier and make her feel attractive without that much effort.
sadly, her options in the bus are Sinclair (who is terrified of her advances and she doesn't want to deal with that), Heatcliff (who can't get over Catherine yet), Yi Sang (Rodion thinks he's gay), Hong Lu (Rodion knows he's gay), Meursault (Meursault) and Gregor (she has already extracted enough self esteem out of him by fucking him since day one).
So she is pretty much prison gay at this point.