Um, is this not statutory rape?
No. In most states it's not statutory rape is the age difference is less that 3 years and as another poster pointed out, the legal age in most states is 17, not 18.
This is what I found on Nebraska...
Debauching a minor; penalty.
28-805. (1) Any person not a minor commits the offense of debauching a minor if he or she shall debauch or deprave the morals of any boy or girl under the age of seventeen years by: