Is it normal to only be able to have an orgasm while standing on my heaf?

Yes, it's true. I can only orgasm when I stand on my head and squeeze my legs together. I can orgasm as many times as I'd like or with as much intensity as I desire. There's only one catch, though.. It only occurs AFTER I do some kind of strenuous squeezing of my muscles down below...such as after I take a dump... So yeah, I poop, stand on my head and then orgasm! My boyfriend gets bummed that this is the only way I can get off... Thoughts please...?