The shower curtain is too short. If your shower curtain is too short, it won't be able to reach the bottom of the tub and will therefore be more likely to billow in. Make sure that your shower curtain is at least as long as the height of your tub.
The shower curtain is too narrow. If your shower curtain is too narrow, it won't be able to cover the entire width of the tub and will therefore be more likely to billow in. Make sure that your shower curtain is at least as wide as the width of your tub.
The water pressure is too high. If the water pressure in your shower is too high, it can cause the shower curtain to billow in. Try turning down the water pressure to see if that helps.
The shower curtain is not weighted. Weighted shower curtains are less likely to billow in than unweighted shower curtains. You can add weights to your shower curtain by attaching magnets or suction cups to the bottom.
The shower curtain is not properly installed. If your shower curtain is not properly installed, it can be more likely to billow in. Make sure that the shower curtain is securely attached to the shower rod and that there are no gaps between the shower curtain and the tub.
If you have tried all of the above and your shower curtain is still billowing in, you may want to consider getting a different shower curtain. Some shower curtains are made of materials that are less likely to billow in, such as vinyl or heavy-duty fabric.
