In many countries the age of consent depends on the context. By the looks of it, the Czech Republic is one of those countries:
The age of sexual consent in the Czech Republic is 15.
Additionally, the section of the Czech penal code 40/2009 Sb. covering “crimes against family and children” contains § 202 which criminalizes a “seduction to sexual intercourse” of any persons under 18 years by any promise or provision of payment, benefit, privilege or profit, for sexual intercourse, masturbation, exposure or similar behavior.