How to tell my mom I want to move to another country to be with a boyfriend she doesn't even know about?

I

Oye-

Are you really sure you want to give up YOUR life for this guy? By that I mean are you prepared to say goodbye to your career, your home, your family and friends all for a guy you are in lust of? I want you to be REAL sure about this, that you know and not "think" you are doing the right thing here. 

There is a huge difference between online dating vs travelling 1000's of miles to be with a guy you barely know! I'm not saying this to shoot you down, but I need you to understand exactly what you are walking into, and to do it with your eyes wide open aware of both the rewards and risks to this potential move.

If you are truly serious about this, then really your Mom cannot stop you from moving! You are an adult who is fully capable of making her own decisions in life, if this is what you want and are sure of it, then go for it! However, don't expect your mother to be supportive of your decisions, and don't expect her to be sympathetic if things go south for you, remember the fallout of your actions is 100% on you and nobody else, don't play the victim if things don't work out.

I actually know of two people who did something similar (both I went to high school with): The first girl met him in Australia while she was on a 10 day vacation, they linked up, and she then would travel to/from Canada/Australia to be with him and vice versa. 2 years later she got a job in Brisbane as an english teacher, and has been there ever since. They are still together to this day, they got married 5 years ago, and she is now expecting her first child with him, due in the summer. The second girl met this guy online, they chatted, and within 72 hours not only did she fly to Melbourne, but they winded up getting married that same weekend! She had 3 kids with the guy, and as of today, I'm not sure if they are still together or not.

My point here is these relationships can work out, but I just need you for your own sake to be sure you are doing this for the right reasons, and not as a way to rebel against your mother for her controlling ways.

Good luck.

After two weeks you hardly know him.

Anyone can be on best behaviour for that period 

It MAY work out but it sounds a potential recipe for disaster.   WHY did you have to hide your meeting up from your mom?   That reeks of uncertainty 

If you move, bag and baggage with some guy you've only met once, you're putting yourself into a potential bad situation.

The smart alternative would be to move there, get your own place and spend time with the guy... he can take you out on dates and you can get to know each other.

It doesn't matter if you've been talking to him for a year or for a hundred years.... you don't know how he is in person. How he treats others in person. And most importantly, how he would treat YOU in person.

If you're planning to go, what does it matter how you tell your mother? Just say it? And if you're scared to talk with your own mother about your life and your plans for your life, then i suppose you're too childish to move in the first place.

Have you considered what visa you might be joining him on?