Bloated female pearl gouriami

[DG28]

Hello everyone. New to breeding but not fish keeping. We have 4 pearl gouriamis (1 male and 3 female) in a 430L tank amongst a variety of other fish. Last week we noticed a female PG getting bloated, she is absolutley huge now and been keeping an eye out for a nest as I saw her dancing around with the male prior to getting so fat. However I dont see a nest anywhere and he doesn't seem interested in building one. He is still interacting with her though. Other than being huge she has been fine, poo is normal and she is eating plenty, stays mostly at the top, swimming fine and still has her colour. She is just fat. Any ideas? Posted a pic so you can see what she looks like. My camera isnt very good so not the best pic. Not sure what to do with her tbh.

 

[DoubleDutch]

I'd say some kind of tumor.