Depends if it is playfully fun... n=maybe what did you have in mind?
Its the use of the word "allow" that intrigues me. Like it is something that the OP takes pleasure from. That's more than a prick tease, that's just plain odd.
But of ruining means getting me right o the brink and then stopping, unless it was done as part f a longer sex session, I'd just finish myself off, and try to spray you as much as I could.
I'm not quite sure how you can ruin an orgasm...
First, why would anyone want to deprive another of a wonderful orgasm unless they were playing a game involving orgasm denial? Secondly, if someone purposely tries to ruin my orgasm, you WILL pay a price for it! Orgasms are special and are to be fully enjoyed until completion.