If the outer ring is pushed inside. If it bunches up inside the vagina. There are virtually no obstacles against its use except a negative psychological perception, and the fact that it is not completely fail-proof against pregnancy. Many men also find it more appealing than the latex male condom. It is not damaged by lubricating oils, as latex is.
Polyurethane is also less likely to cause an allergic reaction than latex.
The man does not have to withdraw his penis immediately after ejaculation, as is the case with the male condom, but can, if he wishes, withdraw after he has lost his erection. Laboratory and small studies suggest that the female condom is quite effective against HIV and other sexually transmitted diseases, although major studies are not yet available to confirm these findings. Some couples complain that the female condom is unpleasant to look at and can be noisy during intercourse. Without sufficient lubrication, it can also be pushed out of place by the penis. Using more lubricant can help keep the female condom in place and reduce the noise.