updating consent in real time during play... how do you actually do it without killing the mood

we had a meet last weekend where partway through i wanted to change something we'd agreed on beforehand but i didnt know how to communicate it w/o breaking the whole vibe. ended up just going along w what wed pre-agreed even tho i was no longer feeling it. came home n felt off about it. how do other couples do mid-play consent updates? do you have a code word, do you just stop, do you have a check in halfway through? i feel like our pre-meet convos are great n our post-meet debriefs are great but the MIDDLE bit, the actual during, weve got no system for. open to anything...