Your Curated Tumblr Experience Awaits!
I agree that no matter the universe he never seems to be the type to use terms of endearments. He's prickly or to driven by paranoia to do that. He cares for his own back that is evident yet as well all know it goes further than that.
If he admits he enjoys someone enough to have a specific title for them the universe may take them. Strip them from his life and leave a once caring name bitter on his glossa. Never able to think of the name or the phrase is hope that if he forgets of them perhaps he'd stop caring.
I agree on the first name bases but I also want to level that with acts of service. He won't call you sweetspark but he'd find that book you've been wanting. He'd may attention to changes you do and tell you that you don't look like a complete dumpster fire. He'd pick at your clothes saying how organics are inferior yet somehow new clothes show up around places you are frequently at for you.
He gets angry. He bites and hurts everyone around him and that wont change. It's who is a has only since worsen due to the war. He's always looked out for himself. He can't change that even for those he cares for. He can better their chances of survival though. Won't risk his own life for another but he'd tell you the fastest exit. And if you were a fellow cybertronain perhaps he make a stray comment on how Megatron is more deranged than usual. He could care little on if you see the medic for you scraps and dents yet they do piss him off when you dont. Your ruining the clean image of the cybertronain race is all
He isn't sweet and never fully will be. To love him is to understand all the angry you must go through. Starscream may never say how much he loves someone but perhaps he can let them know that he's happy their alive. If only for the momment.
honest to god i can't see starscream use any terms of endearments on anyone. i feel like he would call you by your first name and that's it. that's the most you can get from him.