What is reason for male coworker talking about significant other all the time?

Anonymous
I was hoping someone could clear this up for me. I work with a new guy in my workplace for the past year. We started out as friends & since then have been too. He & I have a lot in common which usually makes working in a work group better! FYI, I work in a male dominated profession so I am very used to being friends with all guys at work.

So, in the beginning this guy was trying to be friends with me when he'd always make a point to get my attention to laugh at his jokes or ask my opinion on things. He'd also always come to anything I asked him to attend to help me out (he is in a higher position then me). He also recently offered to 'mentor' me. Then I would notice him staring at me all the time, I couldn't decide why, almost sizing me up? He tends to stare at my mouth and constantly at my hands (maybe daydreaming?). He never talks to any other females at the office. He'll usually stops by once a day to say "Hola" or "What's happening?" to me (his funny way to be buddyish). Recently, he went on a vacation with his girlfriend and his son...he took a taxi to a restaurant I suggested several months earlier in this city and he texted me a photo of himself at the bar there. He asked me upon his return if I got the text from him and he said that he had his son take the photo since he only took his son to the restaurant. He said he wanted to show me he listened to my suggestion and voyaged to the restaurant by taxi.

I wouldn't think anything of the above...other than he was friendly - which I tend to be good friends with a lot of guys. Other than, I cannot understand the staring all the time. The odd thing is whenever he & I eat lunch together or discuss work topics, he always brings his girlfriend up. He talks at length about her - even if we are discussing vendor topics at work, he'll figure out a way to weave it back to his girlfriend. I have never seen this before...obviously always glad to have friends (male or female) who are happy about their lives, but why a constant topic of talking about her again & again to me? I don't even know her! I'd like it if he talked about his son, the weather, sports, something else too. I just smile at him and say "She sounds great!" and change it back to the work topic. It gets kinda old to hear about her 25 minutes per day if we have an hour meeting. I'd get sick of hearing the same thing about cars, or any topic repeated incessantly. The other weird thing is I ran into them in public and he avoided having her & I meet.

Any advice? Why does he do that along with his otherwise non-matching behavior? Is he afraid that his friendliness could be misinterpreted by women at the office? If I am always professional & just friends, why is he incessantly talking about his girlfriend? I want to figure out a way to get us having balanced conversation without offending him since he really is a good friend overall. Thanks!
What is reason for male coworker talking about significant other all the time?
2 Opinion