Just grip your cock, no stroking, and consider that for a moment. Me, in the arms of another man, head nestled in his chest as he fondles these beautiful breasts from behind. You, locked up in your cage, watching him touch and grip and squeeze things you've never been allowed to even breathe on. Watching him run his hands over everything you worship and knowing you'll never have an opportunity to do the same. Watching and knowing that this infidelity is the closest thing you'll ever have to a real sexual encounter.
Watching and knowing that this man has something that I just don't want from you.