I got inspired to write the following message to a decent-looking 'straight / bi-curious' guy who wrote straightforwardly in his profile how he'd like to have a first encounter with a guy happen...

Bravo for writing clearly and honestly what you'd like to have happen with a guy.
You can have exactly that: Damn, you're certainly not alone as you see here.. You've likely got more than a couple of neighbors who're silently yearning for the same thing to happen.. But everyone's too frightened to make the first move. So don't wait for the other guy, cuz he's doing the same thing. I wish you good luck, you hot man!

––––––––––––––––––––––––

It's just working up the courage to risk shooting a guy a slightly looonger glance in the supermarket, a slight body-brush, casually adjusting –and showing him– your itchy bulge while checking out the steaks or cereal boxes, or or.. AND then staying OPEN to see if you get even a very tentative clue back –maybe it's no more than a pause or a barely perceptible nod– AND having a next step already pre-planned.

Don't scoot away abhorred by what you've just done! If you get a response, trust that what you're seeing is actually happening. If you get a glance back, don't immediately assume that it means he's about to punch your lights out. Because if you've caught him as far off guard as you were "yesterday", he probably has no clue how he "should" look back at you: It may take time for the receiver to realize what he's actually dealing with here –and to gather up his courage. Give it time to settle. Walk away. But do come back and repeat. Not lewdly, no licking your lips like a hooker or crap like that, just risk some eye-contact. Damn, that's potent, scary and exciting! Do let him know you're eyeing his crotch and that you want him to see yours. Just convey that you're open, your dick's hot to go and that you want more "radio contact".
Then, if he has fallen into a sort of "suspended state", make a joke about what you're both doing in this same ridiculous place, etc, etc. The worst case scenario is that the guy gets flattered like hell, but just can't deal and pulls away. Best case is that he catches his balance and picks up the dance with you, jokes back, and WHOA!
Have a definite plan ready for this scenario. Slip him a card. Ask what he's doing afterwards.

Neither of you need to know where this is "supposed" to go, so don't let that stop you. That mystery is actually the thrill. The next step is to just get you both to somewhere that's quiet and unrushed. Like your sofa, his man-cave, an outing somewhere.. so you can both sit with it. If you are both curious, that's reason enough.

Life is too short to carry regrets about chances we passed by. Lost opportunities stick like glue and accumulate over time. As I see it, it's better to think back on a few embarrassing misunderstandings and also some super hot times than to have only a series of "what ifs".