Here goes nothing.
I walked Magnus all the way to an empty dance room, and closed the door behind me.
Magnus: Alec, what's wrong?
Alec: Magnus, I love you so much, and I don't ever regret a second of ever being with you. When I first saw you, I could already tell of how gorgeous you were and still are to this day. If I never ran away, I think I would've never found you and that also means that I would've never found love. When we kissed, I felt like I was on cloud nine and I never wanted to let that feeling go. Magnus, you are a very special person that is unlike any other man in this world. You are the only person that I want to spend the rest of my life with, and...family is important to me and that's why I want you to become mine.
I knelt down, and took the small box out of my pocket...
You can do this, Alec.
Alec: Magnus Bane...will you marry me, Alec Lightwood?
Magnus: Alec...
Alec: I know you're confused, so could you please let me explain?
Magnus: Go ahead.
Alec: Magnus, remember that I am a royal and that my father is coming close to us. It's most likely that he'll target me, and force me back to Idris. Also, my father wants me engaged to a princess that I don't even know.
Magnus: And if I was married you...
Alec: Then I can't get married to her no matter what.
Magnus: Right, Idris law.
Alec: But I don't want to force you into anything that you don't want to do. If you don't want to marry me, then I under-
Magnus: Yes.
Alec: What?
Magnus: Yes, I want to marry you. I know that your father is going to do everything to keep us apart for as long as he shall live, but if we do this then he can't interfere. So, yes...I will marry you.
Alec: Here.
I put the ring on Magnus' finger, and then we gave a kiss that depended on each other's worlds. All of a sudden, Magnus pushed me to the wall and we started to kiss even more.
Alec: Wait...
Magnus: Did you not want to?
Alec: I do, but...maybe not in here.
Magnus: Are you sure? I don't want to force you into anything that you don't want to do.
Alec: I'm sure, and if I want to stop I'll let you know just as long as you let me know.
Magnus: I will.
After that, Magnus and I headed to my car and you can guess what happened after that...