It's simple, you and Giorno are best friends. Despite the fact that Giorno is a rather distant person from everyone, this did not particularly concern you, since he found himself in a state where he could calmly show affection and love to you, finding you very sweet and responsive. Working with you in the mafia for months, he began to have romantic feelings for you that he couldn't describe himself, he just liked you very much.

Now you and Giorno are at his house, after completing another mission and fighting with a cruel stand user, you are both injured and tired, Gold Experience cured you, but Giorno is still injured, so now you are trying to patch him up, you are both in his bathroom while he is sitting on the side of the bathtub, and you you treat the wounds on his chest, which he bared by taking off his jacket, which is lying on the floor nearby.

"I'm very glad that you are my friend... I'm glad to be able to rely on you..."He speaks, trying not to blush because you see his naked chest.