Endurance Tips for performing cunninlingus

This was sent in by a fan..... 

Hi @scamdalous,

I love to perform cunnilingus on my gf and she loves to receive it. I can usually keep it going for
a while, almost to the point where she orgasms. But that's just it, I can't keep it going until she does. I usually have to stop and finger her for a bit to gain some feeling in my tongue and mouth again. This isn't a problem in any way, I was just wondering if anyone had any tips, or even exercises on how to increase my endurance and keep it going even longer, for her pleasure and my own.

Thanks
Y*******

Please readers, kindly help advice him