I'm going to use female protagonist and male LI as an example. They could talk about children. Is there a risk for woman to get pregnant and are they going have sex when there is a risk for woman to get pregnant. How that is going to affect the mission. Is it a risk they are willing to take. That kind of discussion didn't happen with Fenris. They could also talk about having children later. Do they want children etc.
Then there are also the sex scenes. There weren't actually any sex scene with Fenris. So that wasn't a problem in DA2. Of course you can solve that problem so that the couple are wearing their underware but I rather see that view angle is set so that you can't see the private parts. But the view angle matters if you are woman or if you are a man.
I'm not sure are there prejudices in DA world. Is it common that woman can fight in a battle field. If there are these kind of prejudices then the LI could comment that he likes to woman because she is different than other women and he likes that. He don't like women who stay at home. Or LI could give a sword to his woman and he could say that he doesn't know is that sword something that woman would like or does she prefer flowers instead. If that woman was a man then something like that might not happen. The point in this case is that is more common to give flowers to a woman and the LI don't know does the woman like that because she is not same as the other women. By the way does gay men give each others flowers?
Why do babies need to enter into it? Couldn't a PC and their Love Interest simply be worried about how their relationship will effect their missions? Can't a LI say "Hey, I get worried about you sometimes" or "the thought of you getting hurt sucks ass", a la Garrus (or, more dramatically, Anders)? Babies and marriage are a touchy subject, even for women. It's also something that holds women back in real life, and I don't think it has any place in escapist media.
Same with sexism. I want less of that BS in my games, not more. Sten questioning whether women could fight was pretty much my limit- and that was actually a useful insight into his character. Anything else just feels like poking and "remember that you're a woman...remember that no matter where you are, or how badass you're supposed to be, people will think you're lesser." No. None of that.
ETA: Oh! And why flowers? Why not something that is useful for any character- like an enchanted amulet or ring that can be worn. There are all kinds of ways to have meaningful interactions that don't call attention to gender, I'm a little confused why anyone would feel the need to go to that well in a game that otherwise treats its protagonists the same across gender, race, and class.