(If I make that any larger Wattpad will take it down.)
Your muse, for reasons of your choosing, had gotten into Alexander Pierce's good graces. So much, in fact, that he decided it was time to reward them. The soldier had been replaced, newer soldiers that were stronger, faster, and didn't require brainwashing to be considered loyal having taken his place. But there was still a perfectly good asset here.
Your muse walked into the room to find Pierce sitting like this with Bucky between his legs, seeming nervous but compliant. He has no idea he was being decommissioned. Or, more so being given a new mission - to serve your muse.
"Ah, I'm glad you could make it. Please, sit. I think you'll like what I have to say next."