I had to move my 3 6" oscars into my 55 gallon hospital because my 160 sprung a leak around the seal. Just a few minutes after moving them my albino and tiger started 'lip-locking' and swiming in circles around eachother head to tail! It was crazy, I caught some video and will post tomorrow. They have never done this and did this for a few minutes. This morning I noticed a whole section of gravel missing and the albino keeping my pleco at bay. I know they are too little to breed but still it was pretty cool!

Don't go out and buy a big fat cigar just yet. Oscars will behave like this from quite a young age. If your Oscars are growing properly, they are less than a year old. Oscars won't be sexually mature until they are at least they one-year-old, they normally won't start breeding until at least 15 months old. This is from my experience anyway.

The lip locking could possibly be aggression because of the move, probably upset them

As you have moved them they are re-establishing their pecking order in the new tank. Hopefully this will settle down soon, however keep a watchful eye on them as they may not like sharing such a relatively small space and one may get bullied and injured