A husband approaches his wife with intentions of making 爱情 with her. The wife doesn't want to, and says no. The husband ignores this and persists, until the woman finally gives in. But the whole time the 'making out session' takes place....

Yes, and it's called marital rape.

Regardless of your relationship status, whether it's a stranger, boyfriend, ex-boyfriend, husband, friend 或者 relative, no means no, and is always considered rape. Several women give up protesting in the middle of a rape, but it doesn't mean they wanted it.

EDIT: From link:

Sexual violence in heterosexual marriage can take a broad range of forms, including coerced sexual contact, sexual harassment 或者 sexual degradation of the victim in front of others, and forced penetration. The latter, marital rape, is the focus of this article. Marital rape is seldom 给 the legitimacy 或者 validity of other forms of sexual violence, but it can be just as devastating. What sets marital rape apart is that the victim has to live with her rapist.

This is most definitely rape. She 说 no and he ignored her wishes, and forced her into it.
Some people may say that since she gave in, it's consensual, but many people "give in" because they don't want to fight, because they're scared, ect.

There was a story where a female soldier was forced into having sex with a male soldier. Not many thought it was rape - she didn't fight him. The rape part came in because she felt obligated because he was her superior - the wife may feel obligated because it is her husband - and the female soldier became depressed and scared. One lawyer finally took up her case and he was punished, rightly so.

I, personally, think it's rape. Her body is being violated, it's as simple as that, and it should not happen, but no one takes marital/date rape all that seriously.

或者 male rape for that matter, but that's a whole different subject...

Well in the beginning I would have to say yes.
She 说 no...that should have been the end of it.

But she 'gave in' later so...

No. Not if she actually agreed to it. If she just stopped saying no, then that could be argued, but consent stops it from being rape regarldless of what someone actually wants, unless they are younger than the age of consent law.
For example:
“Honey, wanna…you know?”
“I don’t really feel like it tonight.”
“Aw, come on!”
“Okay fine.”
That’s not rape. And if we start calling that rape, there’s going to be a plethora of people getting sued and the plaintiff’s claiming “I 说 yes, but I actually didn’t want to.”