Male guppys have very high sex drives as they need to breed alot in the wild to survive as they are the prime food source for many predatory fish. Naturally though there will be hundreds of females in a single lake and there are enough abundent males for them to hang around in bachelor groups without fighting, but when people limit these sociable fish to very small groups in comparison to what they are used to it raises social tention because they guppys instinctivily asociate their small numbers as to somthing that is threatening their species and start to breed even more rapidly.
This is why it is so important to get gender ratios in the right balance, even if say you had 3males and 9females this is not always enough even though it goes by the guidline rules of guppy stocking, you have to take every guppys personality and needs into consideration.
The points of having so many females to the males is;
a. To help prevent agression between the males, when there is a serious lack of females the males will fight to the death and even in a better situation, they will stress each other out no end.
b. So no individual female gets harrassed to much by a male/s, over harrassment can lead to abortion of fry, bring on sickness, end up having birthing complications i.e mother fish dies during giving birth from stress from males- even at best your females simply won't be enjoying their experience with so many males, it simply isn't natural for them.
A freind of mine once had 5males and 2females despite my advice, when one of the young females tried to give birth, the males ate her tail off and she died shortly after giving birth- the had never been agressive to her before, but it shows that doesn't mean it will stop the inevitable from happening...
It sounds like your young females are already getting more attention than they deserve, your male guppys are sex starved with so few females between them so any that come into "heat" will be constantly raped, and it sounds like your males aern't just directing their attention towards the mature females.
You cannot say your fish are happy, simply because fish don't share the same emotions as we do and we have no way of realy telling you they feel, im not saying you are a bad fish keeper or would purposely be less than responsable over your fish, but i hear too often of scenarios where like a person keeps a comet goldfish in a 5gal tank and refuses to get a larger tank for it because "the fish looks happy in its current tank".
The only way you be positivly sure that you fish are doing well is by following done and learned tactics and info like as far as good stocking is concerned and studying the fish's behavior, and that doesn't nesarsarily mean the fish are happy just because the males are constantly mating with a particular female/s.
My advice;
Depending on wether your tank has the space for more, get some more females, if not rehome one of the males at least.
ps: guppys males will mate with practically anything that swims and doesn't eat them, they will even mate with each other, but this is not a case of love or gayness but more a case of dominance over the socialy weaker fish. Many animals in the world practice this.
I dont care what people say. It happens in my tank so i have all the proff i need for myself. One day all my 3 boys are attracted to one female. I have 2 full grown females. There really big. I have an othere female but shes the size of to of the males who are young but she isnt to sexaully active. So one day i would see all three males persueing one female. while the other is calmly swimming on the other side of the tank relaxing. well yeah just wanna say that. I know im not following the male or female ration thing but my fish seem extremmely happy the way they are. Plus i have three female ballon maollies in there that the guppies sumetime take a chance at.lol 
