Not sure how helpful my reply will be, as I was married (and still am!) throughout my ordeal which ended up with my colostomy. With some experimentation we have returned to a full and active sex life. Sometimes I wear something that covers my appliance (like a slinky nighty) and sometimes nothing at all. But he was, of course, aware of it from day 1.
OstomySecrets makes clothing which can hide/hold in place your pouch during intimate moments, even for men, I believe. You might check out their web site for what is available. Also, I ALWAYS make sure my pouch is changed and empty before an intimate interlude, so no unpleasant surprises or odors no matter what.
I guess what it really comes down to is a question which has been discussed often on this site - at what point do you mention to your potential partner that you have an ostomy. You might search for some of these discussions, and see which answers resonate for you.
The bottom line is that you will have to think about this question and come to some conclusions on your own BEFORE you end up backed in a corner and saying the wrong thing at the wrong time because it all slipped up on you. Frankly, I have never been backward about talking about my situation - not shouting it out to everyone, but not keeping silent. But, then again, I have never had to look for a potential partner who didn't already know about it.
Good luck - there have been many success stories here on the site, as well as not so successful. But then, that's life. Even without a stoma, there will be successes and not-so-successful encounters. Keep looking forward, not back, and know that eventually you will find the right person to whom the ostomy won't mean anything at all, because it is simply part of the whole package which is you.