Feeling weird because he asked out a good friend of yours a while back strikes me as pretty normal, but I wouldn't read too much into it, especially that you're coming in second.
First of all, if he asked her out four years ago, she said no, and that was that, then obviously he's not carrying a torch. He shrugged, said "oh well", and moved on. There doesn't seem to be some huge drama here: you're definitely not the rebound.
Secondly, if he's a great guy, and you're dating him, then it sounds to me an awful lot like you came in first. Enjoy what you have; don't worry about what might have been.
Good answer--I'd follow his advice even if you do feel a little weird about it right now.
If it helps at all, I was in the same situation-without the 4-year buffer. My boyfriend was interested in one of my good friends a few months before we started dating. (I don't begrudge him this; she's gorgeous, extremely nice, and a big flirt--who wouldn't be interested?) He also asked out another one of my good friends a couple weeks before we started dating. This one made me feel mildly weird. BUT we've been together 5 1/2 years and we couldn't be more perfect for each other. Just because it wasn't love at first sight doesn't mean it's not the real thing.
Also, we met in a dorm, which is why there were so many date my friend opportunities. This seems similar to your office situation. Do you feel second place to some random girl he met at a coffee shop and asked out 2 years ago? No, so try not to worry about this.
Thank you so much for this! I'm in the same situation, where my boyfriend was interested in my friend before me, and I still feel a little uneasy whenever she's around. Whenever I get uncomfortable about it though, I remember that I'm the one that's with him, not her, and that it's her loss, because he's a great guy.
Glad I could help, and, more importantly, glad you're in a great relationship!
Well, it was four years ago, so it's not like he just went to you as the "next woman". Perhaps during the four years he got to know you more, and liked what he learned. I'd consider this a total non-issue and enjoy your time with him.
If you're all at the same office it's not unlikely that there'd be some overlap with who dates or fancies who, it doesn't mean you're second best, especially after 4 years.
I was in a terrible situation a guy that I liked whom I dated briefly we were working together and he asked out the girl sitting next to me at work without a care about how I felt about it. They would laugh and giggle together in front of me. Work stuff is horrible. Suppose the girl who said no, gets jealous all of a sudden and may want him back.
But all in all you may be okay. But just be on the lookout men willing to date a work sometimes date/hookup with multiple women at work.