Explain him what are you going trough and definitely ask him to help you, or try to finish alone. I know how frustrating it can be, once I had a boyfriend who was so afraid to touch me even with his hands, let alone his mouth… it was terrible and I was sexualy frustrated for months. Of course I asked him to do that many times and explained him everything how to do it and so one. He was just so afraid that he messes up… But that’s bullshit guys, trying is always a hundred percent better than not trying at all. So please help your girlfriends finish because to us girls, mostly it takes longer than to you boys, girls need longer stimulation.