"Oh, come off it!" Tony groaned the first time. "That's not fair!" He dropped Bruce's underwear on the floor and attempted a mental comparison between Bruce and himself. "I thought I was doing pretty good, but you have got to be at least an inch bigger!"
Bruce tutted. "Feeling a bit self-conscious here, Tony. Do you mind if I do a quick comparison myself?" He smirked, his fingers tucked under the waistband of Tony's own boxers. Tony nodded, and Bruce tugged them down, and hummed. "You're doing okay yourself, Tony. I'd say half an inch, at the most." Bruce winked.