Kids are always going to experiment sexually from a very early age, it is part of the growing process but I must admit oral sex seems to be quite an advanced "technique" for 4 year olds. It does imply mimicking something they have seen whether on TV or in real life having observed parents.
It is perfectly normal for kids to investigate their bodies and play with it but what the OP mentions is one step further from this and becomes a very thought about premeditated thing IMO. Oral sex is not just investigating your body and how it functions.... It really goes a little further than that.
However I think one of the worst thing you could do with those kids is make too much of an issue about it. I suspect at that age they are not viewing it quite in the same way as we do and to "highlight" the very sexual disturbing nature of it will only fuel their interest further.
I am not quite sure how I would handle it as a parent to be honest, it is quite a delicate balance between wanting to discourage them in the future but also making it seem "dirty" and thus also giving them a rather skewed view of sexuality for the future.
Our society is overly sexualised IMO. We have this idea that sex is paramount for our happiness and well being, that sex is a commodity whilst also inferring it is dirty and something to be slightly ashamed of.
IMO we need to be far more open about sex to kids but in a very age appropriate and responsible adult mature manner. Because whether we like it or not kids will be exposed to pornography, to the sexualisation and objectification of sex as the be and end of it all in society at large.
We are the ones who have degraded something perfectly healthy and normal and made it sleazy and the damage is going to be hard to undo unless we too start re-assessing our views of sex.
Kids are curious. They will explore, they will question and they will experiment.They are also sponges and they absorb and mimic what adults do. Toddlers now try to emulate the way pop stars and actresses sing , dance, act , dress so considering we seem to revere and put those people on a pedestal it is quite normal for children to assume this is fine and normal.
Perhaps if WE as adults took a more mature approach to sex we could pass on more healthy values to our kids ?
Trying to hide stuff from kids in a world which is so media driven is almost impossible. Not sure how you get the horse back into the stables on that one...
Being sexually repressed is bad, but over-sexualisation is just as bad. We have gone from one extreme to another with nothing even remotely approaching a healthy mental middle.
Nothing wrong with oral sex but between kids age 4 and 5 ? Mmmmm. I think somewhere something might have got a little out of hand.
Kids are not allowed to grow up at their own natural normal pace now but expected to handle more and more at a younger age. Our bodies and minds are meant to be developing at a certain pace.
Sexual experimentation and the discovery and understanding growing up brings is meant to happen slowly so we can not only come to grips with it emotionally and physically but also enjoy the process.
We have made everything about sex nowadays rather than incorporating sex into a normal healthy life. We are sold society sex as the panacea for all ills, and bombarded with images which quite frankly are there to titillate nothing more. And are inescapable unless you retire to a place which has no TV, Radio, Computers or Advertising of any kind.
And yes kids to walk on parents having sex and it will be far more embarassing to the parents than the kids (if they are young anway ). It is not what they see which will scar them but how you handle this. You can choose to go off the deep end or do the brave and mature thing, grab the bull by the horns and explain about sex.
I remember my Dad ( single Dad) who was obviously terribly uncomfortable telling me about such things but who still had the courage at all stages of childhood to explain things to me.
Everything was age appropriate but I was never left in the dark. And if I asked ANY questions no matter how strange he would answer them, albeit with a strained expression !
In many ways I think he got more embarassed as I got older and older ! I was far more informed than any of the girls in my Catholic schools .
He also made it very plain when I was very small that my private parts were not to be be interefered with by ANYONE including himself and that I should immediately tell someone I trusted if this ever happened.
I had not idea what child abuse was at 4 but I bloody well knew it was not right if someone did things to me. Unlike most of my school-friends I was not shocked when I got my first periods and not that embarassed to have and ask my Dad to take me to the shop to get my first bra.Though his face was a picture ! Poor Dad.
I think it must be awfully hard to have a teenage Daughter on the cusp of womanhood he still wants to pretend is his little Girl !
Sex is not embarrassing, it is not dirty, nor disgusting but it should come within an age appropriate emotional framework and this should be explained to children. The mechanics are one thing, the emotions and psychological upheaval which come with it have to also be addressed.