It has nothing whatsoever to do with "wiring" - it's patriarchal socialization that envisions a strict gender binary where you prove your masculinity by not being remotely like a woman (as homosexual men who "receive" penetration have been considered since Roman times).

I get that it can be intense to watch your partner with someone else and that some women have trouble with that as well, but again, that's patriarchal socialization that you kind of own each other, and that guys in particular ought to be "in control" of their women. 🙄

But yes, guys who can embrace and enjoy MFM will typically get to experience a very happy and sexually unleashed woman.