Byakuya had no idea how to be an actual good boyfriend

It really was a mixer of his lack of empathy, his ego, his self-centredness and never having a significant other before you, since you were the only person who could actually deal with him and his "I'm better than anyone because I'm rich and the ultimate Affluent Progeny" mentality

He knew he was a horrible person, hey he wasn't going to lie to himself because he knew he wasn't a good boyfriend as because of him running the Togami corporation, he rarely spent time with you and if he did. He always ruined the mood by saying something snarky or mean to you

One of the Togami Corporations affiliates was having having a ballroom party and Byakuya invited you to join and be his plus one for the party, but it was with rules though as you were forced (Well more persuaded) into wearing a corset and to look perfect

In the limo to the mansion, Byakuya starts talking in his usual stern and demanding tone

“Remember, This are the affiliates of the Togami Corporation and there for not your friends or associates, don’t mess this up for yourself and me”