Friendship getting weird?

Anonymous
First of all, excuse me for my English. Or rather excuse the translation website I probably used here.

So, I have a problem with this friend.

She is the girlfriend of an old friend. She has been his girlfriend for years. But for work reasons she had to move and she ended up, by pure chance, in the same city where I work. And even in the same company.

The fact is that since she arrived our relationship has become much closer. We talk almost every day, inside and outside of work. We meet to eat. We meet for dinner. We got drunk together...

We talk about everything and everyone, for hours.

Among all the things we talk about is, of course, her boyfriend. She only says wonderful things about him: About how much he loves her, about how much she loves him, about how perfect he is in this, about how they both love whatever, about their future children, about their future wedding...

But when the alcohol begins to take control, some subtle bad comments about him begin too. Always hidden among many other good things, obviously.

But the playful glances towards me also begin. The caresses. The whispers...

For small, very small moments, anyone could tell she would be flirting with me. Even me.

Of course she denies that anything is going on in front of anyone who sees us too close together. She even gets offended if anyone dares to hint that there's something between us... But even I'm not very clear about what's going on here.

Her boyfriend comes to visit at least once every two months. And when they're together they seem genuinely in love. She also goes to see him every two months, I assume to keep looking like this in love in the other place.

But even so, none of that corresponds to what I think I see when we are alone.

Maybe it's all in my head. Maybe none of this is real. But I'm starting to fear that she might have some doubts about her relationship because of me.

What should I look for to know if my suspicions have any basis? I need to know your opinion.
Updates
7 mo
PS: No, this is not about me trying to steal my friend's girlfriend. I just want to know what's going on so I know how I should act.
Friendship getting weird?
5 Opinion