This seems a topic better suited to one of the spell sections.
As for the spell itself I personally wouldn't use it for multiple reasons.
I tend not to use the spoken word within spells.
I prefer simple actions or rituals without the use of chant work.
If I were to use chanting I'd use it along with other actions. A candle burning ritual, a sigil working, etc.
I would be entirely put off with the idea of walking up to a couple and pointing at them while saying things.
As well I wouldn't personally care to be on the side of a close significant's anger should they react poorly to my pointing and speaking.
My point is pointing is considered a disrespectful or confrontational act in many countries and areas.
My main reason for not using a spell such as this is if I needed to break a relationship with a significant I'm probably going to do just that. The good old- I don't want to see you anymore.
No spellwork needed. It's direct. It leaves no room for doubt, is clear and letsthe other know how I feel in an honest way without the use of magic.
The example of breaking up a couple as well does not appeal to me. It isn't who I am. Honestly if I like someone, and they prefer someone else I am more liable to simply move on and if I have a friendship with the person I like I am going to leave them alone.
If a friend I like is interested in someone and does not like me the same as I may like them, I'll want them to be happy. They're my friend first and foremost.
If it is someone I don't know well or at all whom I'm attracted to I am especially going to leave their relationship alone.
The spell itself is written fine. It is definitely interesting.
I just personally would rather use a souring spell instead. Less chanting and no need for pointing at people.
It can be cast in the comforts and safety of my home with less chance of confrontation.