Had a couple of ideas and thoughts.
A thought is that since Enamorus was brought forward in time to present everything would look different in the world but she is most interested in the new kinds of sex toys that have been invented and wants to try them all but always prefers the MC's dick.
A crazy idea I had involves Mew (not pregnant), Eternatus and Xerneas. Mew would eventually find out that the MC has a dick bigger than whalelord when with Eternatus so she convinces Eternatus to let her try it. Since she has never tried a dick this big before Mew wants to do something special with it the first time. She would want to take the ENTIRE dick into her in one go and on the first time. To do this she would need a lot of speed and stretch a lot. This is the crazy part. She would drop down from high orbit like a meteor with pin point accuracy (from practice) onto his dick while Xerneas sends life energy to Mew and the MC so no one will get injured and really help Mew stretch her belly.