There is no 'with anyone else', for Sherlock. There is a 'with Tony', but none of it applies. Not whatsoever.

His hands settle onto Obadiah's shoulders and stay there. He makes a soft, thoughtful sound and, at last, opens his eyes and keeps them that way.

Someone is going to have to give something or they will not be exchanging very much information. So far they have gotten the point across that they are both good kissers and intensely curious.