Just Another Saturday Night...

I'm in my early 50s now and have been in an open relationship for a few years. We both agreed it was better to be honest about our desires rather than keep secrets. Last night, I met up with someone new at one of the local spots that caters to this crowd. We chatted for a while... exchanged some banter... then things heated up and we left together. It's not my usual style to go straight into physical activity without getting to know someone better first... but something about this person just felt right. When I got home, I told [partner] what happened. They listened patiently... didn't seem too bothered by it. Is that normal though? To be okay with your partner going out and doing this kind of thing so casually? Does anyone else find themselves questioning whether they're being as open-minded about polyamory as they think they are? Sometimes I wonder if I'm just not cut out for this lifestyle despite trying...