I'm thinking of teasing my boyfriend when I beat him in the videogame on my second try after watching him try for an hour
Why do you need to bring him down?
I want to tease him a bit, not hurt him so much.
While it may be fun, his feelings might be hurt and you shouldn't be so harsh to him. You need to be more encouraging and kinder to him, and let him have all the chances he can get by beating it himself. You shouldn't make fun of him.
Why do I have to give him the time to beat it himself? If he can't do it, I'm going to tease him and make a fool of him for being a failure.
Putting your boyfriend down could affect your relationship with him negatively. If you really love him, give him a second chance after failing the first time.