One can't live one's whole life worried about this. When I (female) ask male colleagues etc for informational interviews, work coffee, other meetings, I face the same problem. All you can do is be clear in the first place and exit gracefully if misunderstanding persists.

"Hey, I'm really interested in your experience teaching kids how to create GUIs using tkinter. Could I ask you about that over coffee?" If there's a persistent misunderstanding that this is a romantic conversation, you just gotta leave it -- nothing else to do.

The natural conclusion of this train of thought is to never ask someone out for coffee to begin with as the OP was suggesting.

If you're going to take it that way, don't interact with humans ever. You do you, my friend. But that's black-and-white illogical thinking. "Once I asked a woman to discuss a tech thing and then she mentioned her boyfriend forever." Who cares? One person had a hangup or a bad experience, and the horrible outcome is that she mentioned her boyfriend a few times. Try again with someone else, guy or gal. Try asking two people to coffee at once. There won't be any tragedies if you are polite and professional.

I care.

I care when a woman takes a totally innocuous statement or question the wrong way and thinks to her self "That guy is creepy."

I care when she tells her friends "stay away from that guy, he's a creep."

I care when she gets promoted and becomes my boss and thinks "that guys a creep."

>the horrible outcome is that she mentioned her boyfriend a few times.

You're missing the point. The horrible outcome is that she will forever hold the irrational concern that you're hitting on her. It will colour everything you say or do.

I think he/she got the point, but just doesn't see it as a big deal. I don't either, though I can understand the hesitation.

The parent poster's point is that you really can't let that bother you, and that in situations like these a thicker skin for awkwardness pared with straightforward but polite communication will serve you better in the long run.

Exactly.

Since my bad experience inviting a female colleague out to coffee, I've never really gotten too socially close to my female colleagues, and it has harmed neither my professional career nor my social life. I have female friends, I just don't make them at work.

There will always be people who take things you say or do the wrong way. That just comes with the territory. If you want to be good at your tech job, you won't be able to avoid working with other people in some form, so you might as well make the best of it.

Your best move is to play the game with both hands above the table, not to avoid playing the game at all.

Here's a suggestion for what to say: "Sounds like there's some sort of misunderstanding. I'm not interested in you as anything more than a coworker. We're on the same team and I need to know how to work with you. If you don't want coffee how about we just chat sometime in a meeting room?"

If they're still being weird about it, then it's probably worth discussing with your manager because that other person is probably generally difficult to work with. Also to cover your own ass from the specter of future sexual harassment issues if that's what you're worried about.

If you're just worried about the other person making it weird... I don't mean to dismiss the concern, but there are plenty of weird people out there, and it's unimportant in the grand scheme of things.