Fingered by my friend's husband(25F4M)cali

Hosted a little Halloween gathering this weekend and went to the kitchen to refill some cheese, crackers and snacks. Friend's hub followed me (I assumed he was refilling a drink) and rubbed up behind me....when I turned around he grabbed my breast, and I didn't really object. (I also wasn't wearing a bra.) He was groping me then slid his hand up into the little shorts of my costume and started playing with me and slipped his fingers into my panties.
I found myself getting wetter and spread my legs a bit to allow him to go on...which he did and gave me an explosive finger bang in my kitchen which was just out of view of most the guests. I came all over his fingers and he just licked my pussy juices off and went back to the main room.
Now I find myself wanting to return the favor...how do I do discreetly offer this? Or do I just ignore it and chalk it up to a drunken "accident"?