Just don't use a condom and make sure he pulls out before coming. I have been with many women, and I almost never use a condom. Never got a girl pregnant, never got STDs.
I don't have random sex. I date a girl for a long time, and really get to know her before we have sex. I always find virgins back in college, so STDs were never the concern.
I was married for 12 years, and have 2 kids. The 2 times I came inside my ex-wife resulted in pregnancy, so I know I am very potent. Currently my fiancee and I have sex
very frequently, and I never use a condom. She is not on birth control because her mood changes and it negatively affects her. It's okay to lose the condom. IMHO.