So true first time my girlfriend (later became wife) was with another man she thought it was wonderful. Years later after several other men, she still claimed it was best sexually experienced ever.
I wouldn't say that there is anything "wrong." You've had a new experience. It's not a common experience and there is no roadmap on how to emotionally process it. So, just take some time and let yourself process it without judgement.
Nice to know it's going so good for you. After my first time with another guy (plus my sweet baby love, a threesome) I was totally addictted, and so is my baby. He and I have been a very loving couple for about 14 years and he's my rock. But I have great sex with several guys and my baby loves watching me with one or more of our guy friends. He also gets with one of my 2 girlfriends now and then and I love watching him have hot sex with another girl. In fact that's how it started with us (I'm bi). Maybe that's not for every woman out there but it's great for us. Just enjoy what you have!!
Apologies, I didn't see what section this question was in when I began to type (I hit new posts) but thought I might still be able to contribute something as a guy. Its understandable you'd have a lot of thoughts going on in your head over this incident and why you had so much pleasure, I suspect more than normal than with your husband. A good portion of this occurring is due to the mentality going on inside you. This isn't just something new you haven't tried before, but it's also not with your normal partner, and therefore, a lot of things in your mind can trigger the "This is so bad/naughty it's good" and you can get carried away. It may also have to do with the guys performance and knowing what to do. Knowing your regular partner is OK with this also unlocks a bit of a freedom mindset where you can just let yourself go. Combined, you'd most likely end up with what you did, orgasming so often. Its not something to apologse for to him, as most guys would see you getting off so much as a major compliment on their abilities. Most guys who give a crap about the pleasure of their sex partner wants them to enjoy themselves. So don't feel bad about it. If you feel guilty about not having that much enjoyment with your husband, or think he may get jealous somehow, keep in mind that this was his idea, and as a grown adult, one accepts the consequences of one's choices. If anyone should feel bad in this situation it should be your husband..... But I suspect he wouldn't feel bad and would have preferred you enjoyed yourself rather than come back afterwards in a negative mindset about the experience he helped push you into. Take the positives from this experience and don't beat yourself up.
That is really super sexy Lena. Be intimate and sexually fulfilling to each other and enjoy the variety as well.