Amusement
So you've been dating this guy for quite some time now - let's say six months, for example - and you think you know him pretty well. He's nice, funny, smart, cute, and he is as head-over-heels for you as you are for him. Maybe the two of you are both members of hero teams too, so you feel completely safe trusting him with your secrets. You have a healthy, fun, fulfilling relationship.
Therefore, when he tells you that he is a metahuman, your first reaction will be amusement.
That's completely natural. After all, your boyfriend is a funny, creative person. You think that it's a joke, albeit one made in poor taste.
But it's not a joke.
2. Denial
Your second reaction is going to be denial.
This reaction is absolutely normal. You've been dating for months; how could he possibly have kept this from you?
And besides, he's your boyfriend. Just because he is a member of a superhero team doesn't mean he has to have powers himself.
No. No way, it's not possible.
Then, he'll feel the need to prove that he has powers, likely with a demonstration.
3. Shock
Now that he has proved his powers to you, you will probably shocked and maybe a little afraid.
Do not let him see your fear.
We both know that you're afraid for him, not of him, but he might not realize that right away.
It is important that you take however long you need to think through and process what you've learned. Take as long as you need - a few minutes, a few hours, a few days.
Once you start to feel the next emotion, you need to contact him, otherwise it might kill your relationship.
4. Anger
Sooner or later, you're going to wonder why the hell he didn't tell you earlier. After all, you're both friends with other metahumans. Then you'll start to wonder whether or not he even trusted you in the first place.
Ask him.
His answer will probably be something about keeping you safe, which is bullshit. This is the twenty first century; you don't need a man to protect you. Explain to him that you thought this was a relationship of equals.
If he feels guilty and apologizes, then that's good. Accept his apology if you feel he means it.
5. Acceptance
Sometime later, you will accept that the man you love has superpowers. You'll realize how scared he was to tell anyone what he was going through, and that he was likely in denial for a lot longer than you were.
He's still your boyfriend, no matter what new abilities he has.
One day it will be completely normal to you, I promise.
You can trust me because I've been where you're standing.
(And if you occasionally make him join you, your sister, and her assassin girlfriend for training, no one will blame you).
