Viagra is an oral therapy for erectile dysfunction we all know this, but the side effect can do you more harm than good, it keeps you longer during sex but have you tried keeping your cash and do a little masturbation few minutes before sex? Sound funny right It's a secret code it works better than Viagra.
She can't know this

I am sure you are a younger man thats why you can masturbate first before the sex,but if you are referring to much older people on whos using viagra because not only for erectile problem but for the longer activity as well
Usually young men can come twice in just single sex thats why you can masturbate first but if the old men did masturbation before sex surely he will never erect again in the bed ,not for at least 5-6 hours again lol