if this is your own relationship you could try the direct approach, but avoid cliche's like 'it's not you it's me' and 'lets still be friends'.
but i'm guessing it's a person you have a crush on who's dating someone, in that case, there are spells you can use, and you can cast as many spells as you want, having enough energy is another story. so long as you have enough focus you can. you know the karma thing so i won't say anything you're choice. if you cannot find love/breakup spells [which i think they're the spells this site was founded on] message me and i'll get you some.