i mean, if we analize, fubuki is the female saitama had more interactions and close relationship with, we can say he's more acquanticies with her than with tatsumaki, most interactions with tatsumaki revolve around insults and not getting along, not until the end of their fight, having a more chill interaction. He protected fubuki from tatsumaki and fought her, so we can say he cared about her well being even being "acquaintances", also the fact that saitama is a big factor in the change and development of fubuki's character.

Then we have Genos, its a fact that he had way more interactions with both sisters, mostly revolving around at not getting along between each other, not until they have big moments for their characters between the 3 during the cadres and psykorochi fights, now developing into relationships of mutual respect and maybe friendship in the future we dont know yet.