You’re bad in bed.
We hate to say it, but if your game out of bed is strong, you might need to look toward what's happening between the sheets.
Sex is an important way to connect with a woman. You might have good chemistry with your clothes on, but if you’re missing the mark with them off, it's unlikely she'll want to sign up for a monogamous relationship with you. If she's going to have sex with one person, it better be explosive.
If you've been under the false impression that showing up for sex is enough to satisfy a woman, get your mind right. Put your selfishness in check, and really ask yourself if you focus on her pleasure enough. From her end, the answer is probably no.