My prada is a seven month old female and she warms up to guys a lot more than girls. She loves playing with new people but she always comes back to sit by us. You might try loving on her after she gets in trouble, and not staying mad about something she's done, I think she can sense it.
And whether or not she likes baths or nail clippings or anything, I think she still knows you're trying to help her and that you love her. Maybe she just likes exploring your boyfriend because he's a little change of scenery. Good luck!
