Yeah, but the point is, those moments come at different times. And only after most of those women are actively implying they're not looking for serious relationships.
Yeah, until they do, and then is when you have to choose if you want a serious relatonship with them. As it should be.
Selina comes across like a textbook casual sex relationship, right up to the point where she doesn't.
And then you can accept her new terms or tell her that you need some more time to think about it. Then you only have to not go with her to the exhibition and her path is closed. At that point, other girls have also stated that they want something more serious with you so the only trap is you telling her you want something serious too when actually you're still playing the field.
Jane tells you she's not really interested in a serious relationship, and you basically have to push hard to get her to come around. (...) in the same vein, Julia saying you should only pursue Jane if you're serious isn't the same as Jane saying she wants things to be serious.
But your sister explicitly tells you the truth behind that behaviour and even warns you that you should take it seriously if you really want something with her friend. In the game's context, after seeing her reaction to your first gig's video (and I'd even go and say in a real life siuation in which they are best friends for so long) you have to be very obtuse to not see that this advice is the real deal and your sister is telling you something Jane would never tell you upfront. And the fact is that you can only ask her out if you tell your sister you want something serious, and then during that first dinner date Jane only becomes really receptive to your moves if you treat her as a serious gentleman would, and she ditches you if you keep acting as a careless youngster. So yeah, if you are actively pursuing that woman for something serious, why would you be fucking around with others at the same time? I think she's even the first one to put you through that 'commitment' choice, so it's just a matter of getting your priorities right: if you really want her and you are willing to be something serious, why would you tell other girls the same AFTER choosing Jane.
And Anna doesn't really have a "okay, now we're segueing from a casual relationship to a serious one" moment - and no, I don't count the Catherine scene because that's not Anna setting the terms.
Erm... no, after fucking her in Cath's ofice she tries to break that casual fling, you have to push her for just a coffee date in which she comes clean with you and tells you a relationship is a bad idea and you should end this right now. Given her background, if you choose to keep pushing it's obvious you're in for a serious relationship. And then you still have that last choice of breaking up with her due to Catherine's threat (which makes Anna avoid you). That's a perfect point to end that relationship if you're still dating others. If you're willing to risk your job for being with her you can't honestly come here now and say you're not serious about her. All your actions say otherwise.
From a narrative perspective, if you were the main character, you could easily be in a position where you agree to a serious relationship with someone because you're assuming one of the other two don't want to be serious... right up until they say they do.
At which point, in the real world, you'd have the option to break up with the original love interest - but in the game, you don't really have that option. Once you make the single choice, the decision is taken out of your hands entirely and you don't really have the option to ever break up with anyone (at least unless/until you're also with Lisa, in which case you get an opportunity to break up on day 14). You're just trapped in multiple relationships until they all break up with you.
First, in real life that would be really shitty of you to accept a serious relationship with someone just because you'd like to start a serious relationship with other girl but you're not sure about that other girl's feelings for you. Because this first girl is trusting in you, and you make her believe that you feel something real for her, but you're actually hoping for other girl to open you her door. Then if this other girl changes her mind and gives you that option (and you happily take it) you are going to break that first girl's heart either way, no matter if you tell her in a coffee or she catches you red handed - yes, I guess you could ask for another coffee meeting as in Lisa's dual paths to take the iniciative but we'd all agree that the hospital scene is just great. Dev went for the effectist option in a narrative license. In the end, you were being a jerk either way.
And again, I'm almost sure there's always a point in each girl's route at which you can break that relationship after the commitment choice but before the final showdown at the hospital (Selina at the museum, Jane at her office, Anna after Cath's threat).