You need to initiate...
I have know idea if your bf is ticklish, but assuming you are intimate, the next time you find him in bed before you, why not walk to the foot of the bed and find his feet...reach under the covers and just begin to stroke his soles as you discuss something unrelated... it will be fun to watch him react as you discuss, say, painting the bedroom a new color... keep your voice quiet, and just stroke his soles while you speak... if he jumps, laughs, say "oh, are your feet ticklish... I never knew that....hmmm" If he seems to enjoy it... get on the bed barefoot and put your feet toward him as you continue to tease his feet, ankes, back of his knees, etc. You may want to flex your toes for emphasis.... next step... run your hand from his foot to his penis, and back to his foot a few times and watch his reaction... I could suggest much more but you get the idea.... he ideally will too! Yes, I have done this too!
Good luck, Tara