I don't know too much about oscars and breeding and I'm sure I dont have to worry about it again but I had introduced a new oscar to my tank a few weeks ago that I had to return the next day because I suspected him of getting HITH, but while he was in there he really wasn't shy at all, he was an albino tiger and he was bumping my lemon albino a lot, and then my lemon (who's name is Bubba) started doing it back and he's not aggressive at all. It amused me so I watched for awhile while they bumped eachother and rubbed around and then the tiger started trying to grab Bubbas mouth and pull on him, I remember reading that they do this before they mate...is that what was about to happen? And one more question, does a male or female initiate it or is it just whoever feels like it?

I think you are referring to lip or jaw locking. This is a sign of Oscars testing each other strength, probably the female testing the male strength. It can also be a sign of aggression so can obviously be a little confusing. Some cichlids can be downright confusing. Two females will get together and act exactly the same as a breeding pair. They may well also do it from quite a young age, a long time before they start breeding.

It's worth noting that Oscars aren't the only cichlids/fish that will lip lock. I have observed my severums doing it, as well as my jurupari Eartheaters.

Lip locking is really common with cichlids. I have had different species doing it to each other. They were doing it to find out who was dominant

My baby oscars do it a lot with each other and my older ones only have done it once that I have seen and thats when I moved them into a new aquarium. Sometimes I will see then open their mouths really wide as they look at their reflection in the glass.

Ohh I see, I thought they only did it for a specific reason. Thanks everyone.