I can only orgasm from working out!?

This sounds really weird, but I looked it up and I guess it’s normal? Almost every time I do side leg lifts with resistance bands on, I orgasm and it feels amazing. I never orgasmed during sex and didn’t even know what it felt like till I got those resistance bands. I want to orgasm like that during sex but it never happens! It’s not like my husband is doing anything wrong either he’s amazing in bed and we do a lot of BDSM kink stuff, which I love. He’s definitely big enough too. I don’t understand why I can only orgasm from this specific workout but nothing else. Ughh, if someone knows any tips for orgasming during sex please comment!