Why would a guy confide in you when he has a girlfriend?

I have a friend who I met through work, we used to be pretty close when we worked together but since then we’ve both found new jobs and moved on with our lives.

He has a girlfriend of 4 years and she seems like a really down to earth sweet girl. The other day he messaged me after not speaking to me for nearly two weeks which I was quite annoyed about. When I asked why he messaged after sometime he said “Can I not message you normally? I wanna speak to you about stuff as I have a lot going on rn”. Which is fine because I know he’s stressed but why won’t he confide in his girlfriend?

Why would a guy confide in you when he has a girlfriend?
Post Opinion