So just tell them to take a couple shots a Jaeger before they get their wii.
You can be childish and immature well into your 50's if you play your cards right, but most people, after a couple years of college, have given up on the high school obsession with doing what the head cheerleader and the captain of the football team do.
Just an example, when I was 19, I bought a Sailor Moon soundtrack tape. I mean, I'm a guy, and I bought a pink cassette tape from the mall near my college, with a picture of a female cartoon character on the front (and this is before Anime had any pretense of being mainstream or accepted). I mean, I didn't brag about it to my friends or anything, but when one of them saw the case sitting on the counter and asked "is this yours?", I didn't feel some great need to lie about it or anything either.
If I could do that, and you 21 year olds can't get up the courage to go into a goddamn Best Buy and say "Gimme a Wii", you've got major issues.