I have 2 gouramis alone in the half tank (i have made a removable thing to make my tank works like 2 tanks). Also I saw them 3 or 4 putting the mouth to the tail of each other , isnt this th.e matin?A bubble nest doesn't mean eggs are laid. Males will build them without females present. Are you sure you have a male and female? Have you actually seen them mate (ie "the embrace")? Are there other fish in the tank to eat the eggs?