Tropical Balloon Molly Fish

Question
I have about 20 tropical community fish and 1 crowntail betta in a 29 gallon tank. They all get along very well and always act like their hungry. I clean the tank on a regular schedule. Always add water conditioner, maintain around 76 to 78 degrees, filtered and air bubbles. I feed them tropical fish food and Betta food. My question is I have a female Balloon Molly that I believe is pregnent but had been like this for at least 3 months that looks like she is gonna pop, ever since i started my tank  the male is constantly up her butt sometimes she doesn't mind. It looks like he is kissing her bottom all the time? Why is he doing this and is there anything I can do?

Answer
Amber,
You have too many fish for that size tank so it is very important that you test your water every 4-7 days. Mollies are not pregnant for that long, but she might be getting ready to breed. With the balloon molly it is a bit hard to tell if they are pregnant or not. It is normal for the male to be checking things out to see if she is ready to breed.