Or ....
1. Report at a suitable time that allows you to fully brief yourself and pass the fuel order etc
2. Advise the Ops people of what you have done
3. At an appropriate time after report time, proceed to aircraft and do what is necessary in liaison with despatcher, engineers etc to facilitate departure
4. When the Training Captain(s) arrive, tell them what you have done.
5. Explain to them that had they been FO's, you would have questioned their reason for late report and noted their explanation for possible future report, then delayed departure until you were sure that they were fully briefed and given them time to 'zone-in'
6. As TC's, ensure that they have familiarised (already) themselves with the relevant facts for flight before departing
7. Most importantly, ensure that everything has been completed as per SOP and do not let their slackness dictate your professionalism.
If that results in a rejection, then walk away with your professional standards upheld and your head held high.