MF4F wife needs a challenger

So first of all: this reddit is from the male of the couple. My wife asked me to find a cake which suits my expactations as a part of her fantasy. She wants a girl that ticks the boxes for me to make her challenge even harder. Her fantasy is to compare her skills to another girl and attach rewards and punishments to the goals she sets.

EDIT: she has this fantasy fo a longer time, even before our relationship and was sparked when i told an experience from myself from the past.

An example of a situation that suits her fantasy: She gives me a blowjob and notes the time it takes her to make me cum. A couple of days later, the beautiful cake is invited over to do the same while she watches. When the cake manages a faster time than the wife, she may choose what her prize will be and what punishment the wife gets. Also, same situation: a set time in which the wife and the cake need to make the man cum as many times they can. Most orgasms = the winner

We are also open for online RP of the situation

Our background: We (m37, f36) are together for almost 7 years, are open minded and have some small experience. Both are well educated. Male is 196cm (or 6"5'), 98kg (or 215lbs), slim but athletic build. For who likes the info: 8,5" equipment (pics on Reddit profile) Female is 168cm (or 5"6'), 61kg (or 132lbs), slim build, C cup, nice ass and waist.

Kinks/do's: be friendly (to both of us) and flirty. cock worship, bwc, cum lover, deepthroat, facesitting, challenges, bets, competitive, gentle femdom, CFNM, age gap, premature ejaculation, cumplay, catfighting (wrestling style)

Boundaries: humiliation in a degrading way, rape, feces, piss etc., pain, blood: No extreme stuff