I realised right now that my previous post was a bit confusing since I didn't really describe my situation, so I edited a bit.
I am in a polyamorous relationship now (only 2 months), a N between my husband, me, my girlfriend and her husband. What I wrote in the first post about having crushes was referring to "the time before poly", i.e. when I didn't regard poly as a viable choise for me (before meeting my girlfriend). Back then I was married and I used to try and control my feelings for others.
Now the situation has changed in that I know that poly definitely can work for me. But I don't feel that, at least for now, I would have the energy or time for a third partner. Thus, I'm still not really able to act on it if/when I like somebody in the future (unless it seems that they do fit into my life at that point). Thus, I wouldn't consider myself available. Therefore, I'm pondering if I still should use my old techinque of trying to control my feelings if/when I meet somebody in the future whom I love, but whom I can't be in a relationship with (for any reason).