I think for a 30 year old, you are very immature if you feel you must spell out sex as s-e-x. It's not a bad word and you shouldn't treat it as such.
Unfortunately, most young people look at sex in two possible ways. First, they look at it as an idealized expression of romance, complete with candles and all the romance they see in movies, and they wish to save that for marriage. Or, they see sex as something fun to do with no repercussions. Both views are misguided. This is why so many young people who wish to wait until marriage eventually have sex anyway. They're sick of waiting for "the one" before they even graduate from high school. Or, they act like wanna-be porn stars without considering safer sex, then freak out when an unwanted pregnancy or STI occurs. They don't know how to handle it. It's a rare person these days who doesn't have a list of regrets surrounding sex.