I'd go with Option 1. But modified.
I am not so sure that being "straight up" is that beneficial here.
I feel like it may be a mystery killer.
So you need to try to get this done through hints.
You may have to turn up the sexuality in your dialogue.
And you may have to carefully screen activities that are normally reserved for exclusive couples in monogamous relationships and that are in love, which you are obviously not. In other words, do stuff that is fun for you, but not things like go to a best friend's wedding, or meet her parents, or shoppinh for mutual item, birthdays, Valentine's day, etc.
Basically, turn up the sexual heat a little, and use dialogue that projects your perceptions of her and the relationship.
I would definitely use the line "You're fun to be around", and maybe segue into something sexual.
Rememebr, a REAL boyfriend in Love respects his woman, and her wishes (Everything to the appropriate degree, always. We punish bad behavior, and reward good behavior. We find out her trutworthines, and act accordingly to her trustworthiness, NOT our ego or programming.). He complies, and defers, and satisfies her much more so than just any other woman. He does this because she Qualified, and deserve good treatment.
You don't feel this way for her, but you still want that P***y.
You need to subtley let her know you're only into her for the sex. Period.
Good luck.