'Certificates' to prove you are clap free. Hmmm... Do such things exist?
Assuming they did exist, you'd need to see her ' certificate' as well; 'to be sure, to be sure' as the Irishman said.
Then you'd both need certificates to prove neither of you had indulged in unprotected sex since the original certificates were issued...
By which time your 30 minutes are up and you're screwed, but not in a good way.
Nah. Won't bother.