An 'F1 Celebration' is when one masturbates in front of one's respective missus, and then proceeds to insert one's finger into one's japs eye the moment prior to ejaculation. Once in the appropriate position one continues to masturbate and achieves a phenomenon that causes ejaculate to spray over one's missus.
This is so called an F1 Celebration because of the similar nature in which a winning racing driver sprays his colleagues and competitors with Champagne.
Joseph: I sprayed my missus like I won the Grand Prix Championship last night.
George: How did you achieve this?
Joseph: I used a technique called an 'F1 Celebration'
Mohammed: Yes, I have heard of such a technique before.
John: You must be highly skilled my friend.