FWB and kissing

Is kissing NOT a thing with FWB? I’ve heard this a couple times now in different posts and subs. Is it because kissing is an act that can lead to catching feelings etc? I’m not sure I could do it without kissing tbh but then again I am in a situation where I’m about to embark on a FWB thing and I certain do not want to fall for this guy!! But I love kissing 🤣