dry sex..

me and my boyfriend have been together for abt 9 months now and we’ve been having sex for a long time and the sex is amazing don’t get me wrong, but for some reason i can’t seem to get wet.. i’ve had no problem with this with previous partners so i don’t understand why this is happening. i’m very attracted to him and there is foreplay and he is HOT!! i love him and im comfortable with him 100% so i don’t understand what’s going on. kind of embarrassing! can anyone help me out or give me some tips??