Love spells are very controversial, and rightfully so. The idea of love spells has been debated time and time again from wiccans, traditional witches, and other occultists.
Mostly everyone agrees that while casting a love spell to help you find the one you're meant to be with is fine, doing love spells on a specific person can cause some problems.
I'm sure you've heard of the old "tale" of the girl who puts a love spell on a specific boy, causing him to dangerously obsess over her. She then has a stalker on her hands. Of course this isn't always the case, and that doesn't happen every single time a specific love spell is cast. While one should always use caution when doing a love spell or having a love spell cast on their behalf, they don't always necessarily backfire.