If you'd like to nominate one of your original characters to be an option in future 50 First Dates pics with Rooth, all you need to do is grant your permission, and supply a reference and some information about your OC.  Selection is entirely up to the commissioned artist, so please, don't bribe the Rooth. ;)

While Rooth values all manner of diversity of interest, thought, and attraction, he is himself of the hetero variety, and as such is only likely to date females.  However, others might be needed for context and cameos in some pieces, depending on the artist's wishes, so having your permission and references available to them increases the odds of you being included, even if not romantically.