It will probably make him uncomfortable or look like you're starting drama, both making it unlikely your plan will even work.
You deserve to date someone who likes you for you, not you trying to be someone else for them.
That said, if it looks like they'll be together for a while, you may want to start trying to get over your crush so you don't get too hung up on him and can hopefully find another awesome (and available) crush!
If you're in a relationship with a narcissist, or someone who you suspect might be a sociopath, it can be difficult to explain what's happening.
This girl didn't do anything wrong by deciding to go out with this guy, so be sure to remind yourself of that often.
Source: Okay, even if you put yourself in her shoes, it's not like that's a magical cure for jealousy.