Balloon Mollys

Question
hi i have two balloon mlly's in my tropical tank they are male and female. i have kept them before and these two i've notice that they keep rubbing up against each other i was wondering if this is ussal or is it part of the breeding they go through

Answer
This could just be them breeding.  That is kind of what it looks like when the male is attempting to fertilize the female.  Do you notice any white spots?  When fish have ich then they will rub against each other and things in the tank.  As long as you see no white spots then I wouldn't worry.