Climax visual effect related to some animations.

[burano]

Not exactly a technical issue, but somehow technical. The climax visual effect, hearts floating briefly around the head of the lucky sim, is said to be random and not frequent. Despite of that, I've found an animations that almost always gives to the two partners that visual effect, and it does simultaneously. It is "lez-B-Honest 07" from Error404Phillips (e404p as signed into the game). Interestingly, it is not a climax animation. It is obvious for me that the animations can be associated with more or less probability of climax for the partners and the point is if anyone can give us some more detailed account of that (how to know that probability about some animation or a general idea of how it works,...).