People who use the word "fun" and "play" to describe sex

Why do you guys do this? It's always been an automatic turn off if a guy tells me he wants "fun". It annoys me because seems as if they're trying to mitigate the idea of sex, turning it from erotic into childish. (And PERSONALLY I've never seen an attractive guy use this term, it's always socially awkward people online or Grindr like apps). Sex is sex, if you have to deflect what it is and aren't ready to accept those psychological boundaries, you shouldn't be having it.