I get vaginal green discharge

Green vaginal discharge is usually associated with infection, particularly trichomoniasis or bacterial vaginosis. It's strange that you say you only have it right after sexual activity though. It makes me want to remind you that your partner should wash his hands before fingering you. I doubt the green discharge is merely related to dirty fingers though, so go to your local sexual health clinic just to be sure you do not have a sexually transmitted disease. If you do, it's always better to catch them sooner than later, so you can receive timely treatment. With luck, all that's required is a simple course of antibiotics.