There's more than one kind of strength.
That's the point, he is not "weak", but can be considered "psychologically weak" because he wasn't able to stop himself from hurting her as she has done with him, in which case she also wans't able to stop herself from hurting him physically, the term was too generalized, in any case "weak" and it kinds should be applied to both of them.
I agree somewhat in the case that hitting back, doing the same amount damage to your aggressor doesn't make you better than her, but again you are being hit and you have the option to defend without hitting back, and you in that moment, you have an option that can make a difference by not hitting her, and then you ask, why is she hitting me, doesn't she has any other choice than hitting me because she just wants to ?, then why I am responsible of an act that has nothing to do with what I have made or I would make ?.
Maybe masculinism hits again: the most powerful ones have choices (men) and governs everyone destinies including yours (women's destiny for sure), as you're the man, self and auto-proclaimed for unexplainable reasons the most powerful of the two (as being said by kosh: there is more than one strength), you're the one who upon weaks's destiny depends, by putting yourself in charge of a situation you're not and was not generated by you, you're what could be cited "making yourself the man".
This is basically throwing the womans to a level so low, that then I would understand why she is hitting you, not only you're understimating her, you're having a totally "I am a so all mighty superior being" perspective, an actitude which would be able to annoy almost any human being...
When you're in suffering because of the pain that other person is making you feel, and you try to make the other understand peacefully that you're being hurt by his/her direct actions physically or psychologically, and even then they can't realize how much it hurts, the only way that you have left for them to understand, is to make them feel the same as you do, that or slowly turning yourself into a timed bomb. It is not at all that you're hitting back because you are going berserker, acting in a totally irrational way.
I hope that you die a virgin.
You will die a virgin, if you just stand there while a girl kicks your testicles into a bloody pulp.
Ditto, scary...though you can get a lot disseases much earlier in the process of being kicked, which can let you in a critical health state.
Oh and if they complain about sexual discrimination then send them to a freaking coutroom where women are favored instead of the men for adoptions and custody hearings. Even if the mother is unfit she still can emerge victorious in a custody battle with a decend lawyer.
Not only that, anybody knows what happens when a woman rapes a man ?, supposing people grown enough to understand rape is not only male-to-female, because of stereotypes he'll be lucky if he gets justice or even help...