hmmm, thats not very good. ..you say you've tried mutual masturbation..is that where u masturbate him and vise versa, or where you both masturbate in front of eachother? (different people have differnt deffinitions) if you can cum easily by masturbating yourself, but you can't seem to cum while masturbating in front of him the problem may be your comfort level around him. if your not all that comfortable with him nude it will take forever for you to cum (which seems tyo be the case) alternatively if you are very comfortable, perhaps he jsut doesnt have much experience with women (i know i don't)...so tyr just sitting there and masturbating in front of him..let him watch what you do and maybe halfway guide his hand in and get him to work it inb the same motion you were using it. if none of the above work, handcuff hjim to the bed and have your way with him...if everything is up to you, you may find it easier to get yourself off.
Try taking the stress and expectation out of sex. Just spend time naked together, touching each other and forget about the orgasm 'goal'. In fact, it would probably help if sex was banned for a week or two. I'd highly recommend getting some massage oil and doing some full body massages (but no touching naughty bits!) just to build up the sexual tension during the ban. You'll learn to become more comfortable with each other, and when the ban is over the floodgates will open!
This is good advice -- I've even read this in psychology of sex books. It's called "non-demand touching." It is specifically about building comfort and intimacy, and decreasing the tension that comes of "goal-oriented" sex that strives for orgasm as an imperative. I've had lots of sexual-type encounters that did not culminate in orgasms and still are high on my list of "favorite times." Blue skies, -Jeffrey