You are not stopped at the airport or put on a no fly list. I have travelled overseas many times. What they will do is report your travel to the destination country, especially if you are travelling to a country known as a destination for child sex tourism, such ss Mexico, Philippines, Thailand, etc. Then the destination country will.most likely deny you entry and send you back. Homeland Security/ICE gets uour travel information from APIS, the passenger system every airline has to provide information to. The government checks the names of every passenger against a database of terrorists, sex offenders, etc.