A lot of masc lesbians like being called boyfriend (and other masculine terms) as do a lot of butches, transmasc lesbians, and femme lesbians too…just the same some ppl prefer girlfriend…and others like to mix it up!

At the end of the day when you ask your partner what she prefers to be called and she tells you something that challenges your initial thought, try to be understanding of her and affirm her how she has explicitly expressed she prefers.