I don't think it's very femme. I think some guys stay away from purples because it's been identified with the gay movement, but I don't think anyone's going to think much of it, especially if you're not really presenting yourself as a straight man. (And hell, if straight guys are wearing pink now, I think purple tattoos are fine). And, if you're getting more tats it won't draw much attention, especially if all your other tats are very masculine.
I do agree with MangoSlayer, I think darker lines will makes it seem more masculine.