The pairings that would match for me are:
Mer-Man & Octavia - he'd sweep her off her tentacles
Buzz-Off & Sweet Bee - they'll pollinate well together
Tri-klops & Peekablue - his 3 eyes will pop out looking at her!
Flip Shot & Angella - to me they match, the ace and queen
Scorpia & Crita - what the hell, they'll hook up nicely for some reason
Mossman & Perfuma - watch out for that poison ivy rash
Netossa & Spinerella are already an item before UBII
And for a one time hook-up, Chef Allen and Madame Razz would shake and bake it!!