What are you going on about? You think throwing about "cis" and "heteronormative" means that you're making some sort of informed point? You're not. They're meaningless words in a discussion about a man asking about flirting with a woman he finds interesting in public.

You're derailing the thread in order to inject annoying gender theory buzzwords.

Yes the majority of relationships are heterosexual men with heterosexual women. This is undeniable and so obvious that -again- you're being silly.

And yes OP could pressure her verbally or physically but that's not necessarily what he will do. Most flirting between men and women in a public space is pleasant or at least inoffensive. He's asking about how he might go about having a pleasant conversation with some light flirting in order to learn how to avoid having a conversation that might be perceived as inappropriate and your only advice is some useless mumbling about how everyone should just keep their yes on the ground and not talk to each other on trains.