my boyfriend doesn't know if he ejaculates, is this common??

In the past when me and my boyfriend have had sex he can usually feel if he is about to ejaculate or not he lasts really long and it's really good and everything but lately we've been using the pull out method and he can't feel if he is going to ejaculate and that is a little worrying due to us using the pull out method and I was wondering if there is any reason behind this and if it is uncommon