There were days when the realization that he was someone’s father made Steve's head hurt. Mostly he was grateful that he could trust his instincts, because Peter was what had been missing from his life. Yes, he still had lingering, unresolved issues from his time in the Army, and sure, he had what Bucky annoyingly referred to as a criminally untapped ass and no life outside of work and Peter, but Steve was okay with how his life had turned out because of trusting his instincts.
Unfortunately, those same instincts had straight up betrayed him by going absolutely haywire upon being exposed to Tony Stark.
Veteran single dad Steve runs a tattoo shop. For his 40th birthday, Pepper arranges for Tony to get that tattoo he always wanted, and he winds up with the mother of all crushes instead. Jumping out of airplanes is one thing, but falling in love is something else entirely. Steve struggles with the idea of actually letting someone into his life. Tony is left trying to keep his heart from being broken while Steve figures things out.
When Tony starts at MIT, he's excited to finally be in the same city as his older brother, Bucky, again. Then he meets Bucky's roommate and best friend Steve Rogers and falls faster than he would have ever thought possible.