Good for him! I was in his shoes once. The Sweetie was dating someone else when we met. I kept my mouth *shut* and my eyes *averted* until she was single again.
Pod -- am so glad James made that decision as there is nothing to gain by telling her (but they could both lose either other as friends). I was not quite in his shoes (or Ms_Cellany's shoes), but DH was dating
someone else when we met (I didn't know; he told me after he and I started dating
a few months later). I was interested when I met DH. DH, it turns out, also was interested but wanted to respect his relationship
(even though he'd been trying to end it before I came along) so he only interacted with me when he had to (he was my sponsor for my confirmation). DH never told me of his interest in me until he'd been free and clear for 2-3 months (and we've been together ever since then).
We are friends now with DH's old girlfriend (she was even one of our wedding guests), but that didn't happen right away. Also, even though she knew he wasn't the right guy for her, we choose not to share with her that DH *was* drawn to me while he was still in a relationship
with her (again, nothing at all happened, but it would serve no positive purpose for her to know this, especially since, when she found out he was sponsoring me, she was concerned that he'd fall for me, and he had to reassure her that that would not be the case as he was in a relationship
with her -- she even mentioned it to him again when he broke up with her).