In the life of every father sooner or later the moment comes when the wife goes to her well-earned rest and he is left alone with his own child. Does not seem like a difficult thing! That is what Ihor, Artem and «Sauna» thought too, without realising what a  «waterfall» of adventures was falling over their heads. 

Tired of the «joys» of parenthood, the boys meet their old friend – St. Valentine. Relieving stress over a bottle of whiskey, boys jokingly dream of their children becoming adults sooner. 

In the morning, shocked fathers realise that their dream has come true and that they are about to experience firsthand what the saying: «Big kids are big problems…»  means. 

But the trouble does not come on its own, and among other things – wives return from holiday with their maternal hearts feeling sick.

It is difficult for boys to convince girls that these are their children. As a result, they all go to St. Valentine.  

But, Valentine disappoints them: there is no solution to this problem. The only possible solution is for the saint to become a human being, a mortal, and then all the spells will be lifted. To do this, Valentine’s beloved woman, a famous American singer, must kiss him. 

Together with Valentine, the characters go to Las Vegas – the capital of gambling, where through the irony of fate, they must risk everything to save their children.