Why reeinvent the wheel? As much as as condoms ruin not only a guys pleasure, but a girls too (they can feel a difference too you know) but they're as close to perfection as we're going to come without a cure for all STDs and a sure fire way to prevent pregnancy. If anyone tells you a condom isn't 100% they either have never had sex or used an old condom that they didnt inspect. They fucking work, 100%, shut up.
If you're in a relationship, just pull out. It's harder than you'd think to hook up with someone and have her get pregenant. There's only about 2-3 days of the month when she even can, and even if you push when you shouldve pulled sperm has a lifespan of I think 4 days, giving you a window of 7 days of the month she can actually become pregnant.
Just pull the fuck out when you're gonna come and let it be that. Been workin for a very long time.
You're only in trouble if your girl is turned on by the feeling of her man getting off inside her. That's a quiet fetish alot of em have, and you're on your own for that one