We men are insecure creatures. My suggestion is that you be COMPLETELY open with him as you just were here. Tell him your thoughts and points of view on the differences between sex and love. There is indeed a difference. Make sure you let him know that it's not because you want to sleep around, but that you want to explore something new to try and make you being away easier for everyone. I've always found that honesty is indeed the best policy, and although there are tough conversations that come out of honesty, they are necessary ones.
Good luck and please let us know how it goes.
Live life to the fullest 'cause you never know if you're gonna wake up tomorrow!