Starfire giggled at Beastboy antics, admired Cyborg's car, and dutifully trained with Robin. She washed the dishes, slimed Silky, and cleaned her room. Starfire generally seemed like a naive happy little girl, and she didn't mind that image. Her often bemused teammates overlooked her strange habits.
Raven rolled her eyes at Beastboy's lame jokes, helped build Cyborg's car, and dutifully trained with Robin. She read her books, meditated, and guarded her room. Raven generally seemed like a sarcastic, moody, emotionless, teenager and she didn't mind that image. It made living with her hormonal, demanding, crowding teammates just a little easier since they generally left her alone.
The two girls were Teen Titans and took their jobs seriously. Starfire blasted evil away with her starbolts. Raven crushed evil with manhole covers and large trashcans. No one noticed Raven stuck a little closer than normal to Starfire when they fought an enemy. If anyone saw Starfire go into Raven's room, they raised a surprised brow but ignored it. Robin noticed Starfire trying tea one morning, but thought it was nothing. Beastboy noted Raven seemed more unguarded when Starfire was present, but shrugged and tried to make the dark girl laugh. Cyborg scratched his head, trying to figure out why the lights in the hallway kept flickering again.
All in all, it was a normal chaotic life in the gigantic T building. If anyone noticed Raven faint smile for Starfire or Starfire's exclusion of 'Friend' when she said Raven's name, well, no one said anything.