I thought we were friends. Now we are both going for the same job.

Q: Five years ago, I reconnected with a fellow graduate through an online dating site. He complained nonstop about his then-job. I didn't see a romantic spark, but invited him to stay in touch because there might be an opening for him at my federal workplace. About a year later, he was hired after I sang his praises to the hiring panel. We used to spend a lot of time together, hitting the gym after work and being each other's confidants.

He said some things after he was hired that suggested he was disappointed I didn't choose to date him. I was the last to hear when he got engaged.

Now our supervisor is retiring, creating a promotion opportunity that I've been waiting on for a decade. My co-worker has been acting weird since the announcement, launching into soapbox speeches of changes he wants. I changed my gym hours because hanging out with him has become unbearable.

I've learned he is also applying for the promotion. I saw it coming, and I know he must have felt too awkward to tell me himself, but I hate that I heard it from someone else. At the gym, we used to discuss the future of our department, always under the understanding that I was the logical choice for supervisor. He used to ask a lot of questions about what I would change. Now I feel like I can't trust him. Any advice?

A: I included your short-lived dating history not just because it makes a nifty Valentine's Day hook, but also because it offers context about how you two communicate (or don't) and what you can expect from him going forward.

Your history indicates he's happy to receive the information and favors you willingly supply, but keeps his own cards close to his vest. Despite all the time you've spent together, much of what you know about him seems to be based in inferences, assumptions and hearsay. Maybe he's just reserved in general, but I think you have to consider that there may be a strategic purpose to his reticence - i.e., while you thought you had a bridge partner, he's been playing poker.

For example, complaining about his job won your sympathy and got you to open doors for him; telling you about his engagement would have generated no similar benefit. And if he knew he was interested in the promotion even as he was encouraging you to spill your ideas, then he was treating you as a competitor while you were treating him as a confidant.

Of course, just because you recruited him doesn't mean he should automatically step back and "let" you have the promotion. And you don't indicate what makes you the "logical" successor besides seniority and patience. Finally, your cutting off communication makes his failure to give you a heads-up about his plans into a chicken-or-egg situation.

But what's done is done. Now the question becomes how you will deal with whatever decision is eventually announced. One or the other of you is bound to be disappointed, perhaps bitterly, at the hand you're dealt.

Whether through skills or schmooze appeal, if he gets promoted, will you be able to respect his position?

And if you are the one promoted, history suggests he'll withdraw and make comments to indicate his disappointment at not being chosen. Can you trust him at your table?

Before the announcement, you can make one last attempt to lay your cards on the table and invite him to do the same: "I know both of us applying for the supervisor's job makes things kind of awkward. Whatever happens, I hope we can agree to have each other's back." In the meantime, work on your poker face.