If done responsibly (avoiding unwanted pregnancy), sex is no different than massage, acupuncture, or any other treatment of your body.
Is it immoral to mutually massage each-other with your friend in the weekends?
Of course not.
It is completely moral to ask your friend who is a girl for a massage, but it would seem traditionally immoral to ask her for sex, the same way as you ask for a massage.
In reality both are just a dopping for your body, nothing more.
We arrived to the age when we are in control of ourselves much more than our instinctive savage ancestors, so we are able to have responsible sex.
The reason why sex became culturally regulated is partly because people were irresponsible. They bred children without wanting it.
They were not able to enjoy some nice oxytocin without breeding children.
This was a practical reason.
The second was because promiscuous people were not considered beneficial for the society, but it’s the same reason: they were aware and afraid of the chaos resulting from people breeding children while beeing promiscuous.
That would have messed up the well established system of families and lead to impossible situations.
Plus, the danger of STDs.
It’s up to our intelligence, culture and technology: how responsible we are regarding STDs and pregnancy.
So I believe the reason it became immoral it’s a purely practical reason: it messed up the society system.
That is why is more and more accepted (to be “immoral”) because we have contraception technologies, and cure for stds.
Plus, the norm for sex is much more varied today: forms of no risk sex are more widely practiced i think (oral and manual sex).
People have more control, more understanding, they don’t go after blind rules anymore.
Teens they pretty much get away with no risk sex without causing any trouble.
It’s a matter of culture, consciousness, technology and responsibility.
So the answer is: so far you and your friend with benefit are conscious and responsible, it’s not immoral.
When we learn to not cause trouble with it nobody can blame us anymore. 😉
Depends a lot also on the culture of sex.
If you practice a savage, wild, brutal penetrational sex mostly in an unconscious state, you are more exposed to the risks.
This is much result of the sexual culture.
But there are ways to have responsible sex, definitely.
And as more responsible we are, as less immoral it will be.
Nobody can blame you for anything if you don’t cause trouble.
The problem is that people are assumptive.
Sex is what it is: and nothing more. It doesn’t mean that i will be your slave forever, or I’m going to marry you or that we are best friends. It only means that we mutually help each-other to feel better. That’s it. People assigned marriage to it and friendship and all, that is why people are assumptive.
Sex should not be the currency of friendship, marriage, status or anything else.
Status, friendship and marriage are all nice, but don’t measure them with sex because they are not sex.
Our cultural system is using your sexual desire to lure you into marriage or into gaining status, by making sex legitim only in certain conditions.
Sex is always legitim.
It is what it is and should be not used as a currency or to achieve something else with it.
It’s not more or less valuable than it is.
Sex is used for the slut shaming purpose of jealous men, women use it to lure men into marriage (will have sex only after marriage).
Sex is a big dependency of ours, and people are using it to achieve something else with it, to regulate the society system with it.
Our sexuality is misused, just like drug addicts are misused by making drugs expensive and illegal.
When a woman tells you that she can have sex only when she is in a committed relationship, she is lying. She is lying also to the true herself.
Partly she is afraid of slut shaming (which is done by jealous and unhappy men or jealous and unhappy women (but mostly men)- they use sex to shame you),
and partly she is using sex to make you committed to her.
The truth is not that she cannot have sex outside of marriage, but: she just doesn’t want. Because she has some plans which are more important to her than her own sexual desire: using sex as her currency. As her reward. Because you married her. Or dated her.
So as you see sex is used as a means to manipulate.
When somebody is honestly sexual, with a true desire, will not use sexuality as a tool. Will live sexuality instead.
True sexual feelings are a sign of inner happiness and spiritual accomplishment, of high consciousness and originality. Many people who listen to rules instead of their heart, cannot achieve this level.
When you are able to want sexuality itself and not only to manipulate or control with it, then you know that you are doing well.
You can be also naturally asexual of course, but the rule is still the same: you should treat sexuality for what it is. You should not misuse it or turn it into a mere currency of your other interests. Our culture is not yet fully on the level to use sexuality for what it is. They just know it’s something very influential, so they use it as a means of controlling others.