As the other couple commenter have said, it's perfectly acceptable to be attracted to one sex more that the other, even if that means you're more hetero leaning. I'm pan, (used to identify as bi) and a close friend of mine is bi and all throughout highschool we use to joke that I was more straight than gay and he was more gay than straight. Point is, it doesn't matter how skewed your balance is, you're still bi if you are attracted to men and women. Don't hold yourself to some imaginary standard, you are valid just they way you are.
It's a milk mustache. This is an ad for milk back when they thought it made your bones stronger