Finally! We did it. My BF successfully fisted me for the first time. And it was pretty spontaneous.
We started just as sex, but ended up with little finger playing. One led to two, two led to three, three led to four... than five... than he managed to insert his fist whole. Wrist and few centimeters more. It took me almost 2 years to make him agree to try it. It took me years of stretching with toys... I know, long time. I don't have big toys, only last year I ordered a big toy, which isn't as big as fist. We didn't try fisting often... this was actually our third attempt... third time the charm. It felt great! It didn't last long because I didn't want to overdo the first time. It was too arousing anyway... orgasm came soon. I'm actually very surprised by my BF's reaction. He loved it. A lot. He explained how he experienced it, and what he felt, with a lot of excitement. He's already taking about next times and what should we do, how to stretch me more and stuff.
Right now I'm happy and excited. I do feel a bit weird tho. It happened few hours ago. my intestines feel a bit weird, which I believe is natural considering I just had a fish shoved up my ass. I "pooped" a lot of slime... partly bloody slime. (Not sure how you call it in English. English is not my first language) But It's to be expected.
I shall give my ass some time to recuperate...  not sure how long. I guess until I feel ready again.

I'm 30 yo and my BF is 32. We're together for 3 and the half years and plan to be together forever. This little thing actually brought us closer together. Today is the first time he called me his husband (even tho we're not actually married).

I'm happy to share my happiness with you guys! I know I wasn't really an active member. I came here to look for information and guidelines. Now I can call myself a proper member too.

First welcome, and second, congrats!  That is quite a milestone, and yes, some pretty intense feelings.  Hope to hear more about your experiences.  ~f