<human>: Summarize the given text in a few sentences.

I've been friends with this guy, let's call him Henry, since high school. We're pretty close, moved to the same city after college, and talk every day. About 6 months ago I started texting his girlfriend, Mary, pretty much daily. We have a lot in common and it's nice to have a close female friend. Sometimes we'll talk literally all day.

Henry is totally aware of this and fine with it because he trusts us both. However, I've just felt myself lately developing really strong feelings for her romantically. I know this is wrong and I do not want to hurt my friend. I've been single for a couple of years now so maybe it's just loneliness. I don't know. She's never crossed a line in our texts and we rarely hang out one-on-one. I would never blatantly flirt with her or let my feelings be known. It's cliche and silly but I feel like I'm falling in love.

Normally, in such an ethically precarious situation, I'd just cease all communication with this girl. But in this case, Henry will think that's strange. I mean, why would I just start ignoring his girlfriend for no reason? She would think it's weird too and I want to emphasize that she's never said anything remotely showing interest in me. Our friendship has been totally platonic, at least on her end (from what I know). What do I do to stop these feelings? I don't want to end my friendship with either of them.
<bot>: I feel like I'm falling in love with my friend's girlfriend. I don't want to hurt him, but I can't end communication with her without giving away my true feelings. How do I proceed?