Paying CS to child over 18 vs. custodial parent

[short4j]

Hi.  My stepson is over 18 and about to graduate high school.  CO state laws say we have to pay until he is 19.  He is going to college in the fall and we would like to know if we can pay HIM our CS, since his mother does not use the money for him mostly anyway.  I think we read somewhere awhile back (but now can't find it) that if he's over 18 and changes his permanent address, then he can collect CS from us directly instead of us paying her.  We don't mind paying him, and would rather give it to him to use for school than giving it to her to make her car payment.  Any help or guidance is appreciated.  Thank you!

[ocean]

No  you have to pay mom. Away at college is not a perm. address.