Help with a book name!!

[Caroline]

I need help in remembering the title of this book or the series. The SL is so faint in my head so I hope someone is able to help.

I remember it being a biker book, the younger sister (16 or 17 yrs) of one of the bikers was going out with a prospect . She likes this prospect but there is chemistry between this girl and one of the older bikers.

Another clue is that this older biker gives this girl birthday presents every year and is very protective of her.

They don't have a book out for them yet but I need to remember the name of the series.

Please HELP!!!!