It might sound cold-hearted, but this is what I think.
It might seem a bit cruel, but this is how I really feel about this.
ーIt might sound cold-hearted, but this is what I think.
「薄情に聞こえるかもしれないけど、私はこう思う」
It might sound cold-hearted を使って「薄情かもしれないけど」を表現できます。
cold-hearted で「冷淡な・薄情な」
ーIt might seem a bit cruel, but this is how I really feel about this.
「ちょっと薄情に思うかもしれないけど、私はこう思う」
It might seem a bit cruel を使っても「薄情かもしれないけど」を表現できます。
cruel で「無情な・薄情な」
ご参考まで!