Rumlow has his birthday during an assignment in Berlin or Barcelona or wherever cool nightclubs actually still exist. Since all three of them wear tac gear that's as sexy and fetishy as it is useful, they decide to go to to a bondage club all suited up. Brock and Jack spend the evening getting shitfaced and grabbing/manhandling women and even loving it when they get slapped/horse-whipped for their efforts. They order the Soldier to sit on a bar stool and be good, not to do anything even when men and women start petting, fondling, and humping his leg because he's just sitting there looking gorgeous. Also they make him wear the teflon mask because why not.

Bonus if Brock's flirting techniques get him into trouble with some lady's man and even though Brock could totally handle it the Soldier (protective as ever) goes apeshit on the guy.