Sophie's Choice: Kid's Saturday Scheduling Edition

I knew it was bound to happen, but I still wasn't prepared for how to handle it. The 6 year old has been invited to a birthday party and has a soccer game at the exact same time. There is no way to do them both. We will have to choose. 

The husband's initial reaction at the scheduling conflict was, "party." The birthday party is for a close friend, would be fun for the whole family and will most certainly involve cake. 

BUT. 

I began to wonder if we let him pick the party, what are we teaching him about commitment to team? Are we insinuating that it's okay to pick the fun thing over the obligation? Will this make it harder to get him to practice/Sunday school/anything he just doesn't feel like doing? 

OR. 

Are we making too big a deal about what it means to participate on a 6 year old soccer team? I mean, if we're ever going to blow off a game for a fun thing, it would be now, right? And it's not like we're letting him skip to watch TV or play in the yard or because he doesn't feel like it. It's a special circumstance. 

And there will be cake. (I clearly have a problem with sweets lately). 

UGH. 

So, dear Internet friends, oh mothers of experience...am I overreacting?