My boyfriend can no longer give me an orgasm

1

Dear MUB,

            I’ve been in a relationship with my boyfriend for the pass 6 years and up to this day he is unable to give me an orgasm. He has been there for me more times than I can count, and I am really in love with him, but this is becoming a serious problem.

Sadly, I’ve slept with 3 other guys, but only because I wanted to find out if I was the problem. I have absolutely no feelings whatsoever for anyone of them. However, it turns out that the problem is definitely my boyfriend.

I really don’t want to continue sleeping with other guys for sexual satisfaction, but I am tired of being unsatisfied. What can I do?