Optimus Prime:
Optimus Prime is very shy about things like this. He really likes you, but he's never sure when to tell you!
If you like him and don't say anything first, you may never find out!
Just kidding, he'll figure something out.
Firstly, he'll wait til you're alone.
Secondly, he'll make sure the mood is appropriate. He wouldn't want to tell you if you're angry or bawling your eyes out.
When he tells you, he is stuttering. Primus help him.
When he's done, you're in shock. There was no indication that he had been interested in you prior to this.
He's very confused. What about all those subtle hints he had dropped over the past few months?
Those hints must have been too subtle, you guess. He wasn't confident enough to really put himself out there. Regardless, it doesn't change the fact that this handsome mech is head over heels for you. You let him know you feel the same way.
Now that it's all out in the open, he feels comfortable enough to ask you to go for a drive with him. Of course, you say yes, and you hop into his truck and speed off into the sunset, just like in the movies.