I think this thread has been worthwhile even if it was just to raise everyone's concerns and to feel you have considered them and are still happy.
I can understand this being a better alternative to breaking up and a better alternative than fucking nameless people on one nighters. However don't underestimate the emotional element of sleeping with the same person regularly. There is scientific fact that for women it releases a chemical that bonds them to that person which is why women find fuckbuddy relationships much harder than men. So even if your partner is able to disconnect afterwards, the OW may not and could start wanting more from your OH down the line. Its a funny old situation and whilst its easy to compartmentalise arrangements and feelings at the beginning, they have a way of getting all muddled and fuzzy down the line.
^'Oxytocin is a hormone that both men and women have. It is released in our bodies when we orgasm, and also during childbirth. Oxytocin is sometimes called the “love” hormone or the “cuddle” hormone, and that’s because it increases our levels of trust and can make us feel more connected to that other person. Oxytocin is also one of the hormones that helps a mother bond with her baby, which sort of explains a lot if you think about it.
A lot of women will report feeling a connection with someone after sex, even if they don’t quite understand that connection. A lot of women will also say that they feel closer to their partners right after having sex. Both of these things are results of oxytocin.
If both men and women experience the release of the hormone, then why is that guys don’t feel that same attachment after sex? While scientists don’t know everything there is to know about oxytocin, they have found that estrogen seems to increase the effects of oxytocin, while testosterone kind of shuts down those effects. So, since women have more estrogen, and men have more testosterone, women feel the effects of oxytocin way more'.^