There's a deep, profound need to do what we do - to continue to try tricks over and over and over again, despite the painful crashes, opened shins and bloody elbows. And we don't do it to conquer somebody else, or to be dominant over another person (unlike other sports). We do it for ourselves - which is why a rider can pursue his passion on a clunky, mis-shapened ramp in a field, in the middle of nowhere. By himself, lost in his world.
So, you take these qualities which are inherent in people driven in an individual sport, and you attempt to have a relationship with them. The initial thought will be admiration for what he/she does. But once that wears off, the reality of it all begins to set in. And this is where the the potential problems can come up.
BMX riders need to ride, and for each one of us, it varies. Personally, I need to session twice a week. Any more after that is just gravy, but a minimum of twice a week is what I need to stay sane. Otherwise, I start to lose my mind a little. Some folks need to ride more. And depending on where you live, this can be really shitty in during the winter months.
BMX riders are better people when they are given this session time. All the pressure of the work week, family stress and all around bullshit is washed away with a good BMX session. We are not going out for the whole day in spite of you, we are doing it because riding makes us better - and easier to deal with - people. We are also not doing it necessarily to get away from you. If your significant other is emotionally mature, they aren't putting their friends ahead of you - even though it may feel like that at times. Be happy that he/she has friends, because nothing is creepier than a person without friends.
BMX riders can also have the tendency to obsess over things. Or "put on blinders" as what best describes me. This is why we will try over and over and over to land a trick. Sometimes that can take years, and yet we will do it over and over and over. It becomes an obsession to land that one trick.
You, as that rider's significant other, must step in when the obsession starts to devour him/her. Personally, I can use a "Snap out of it!" when I start to obsess over something - like dialing in my bike or riding too much to the detriment of the other facets of my life. YOU must tell him/her to spend time with you. We want to, but it takes a nudge sometimes.
Earlier I mentioned "admiration" for what he/she does. BMX riders need that positive reinforcement, so pay attention to the pictures and videos and progression your significant other makes in their riding. Congratulate them and cheer them on. Share the pictures of him/her with your friends and brag about them. We want to feel like the crashes, falls and pain is worth it to ourselves and the ones we love. Admire that BMX rider in your life, because there aren't many of us. And as athletes, we are very unique.
BMX riders aren't difficult people - we are just complex. We are difficult to understand by many because that passion for riding runs deep. I don't know one BMX rider who rides for "exercise". We do it because it is that time that makes us feel golden; when we can shine. We want to share that passion with the world, and if he/she loves you, we want most to share it with you.
Pull us in, but let us go ride, too. We will always come back.