Soviesu is infertile, Navier was probably not but we really don't know.
When they divorce and Navier's new marriage is approved just after they solve the marriage and the weddings are going to be so fun to watch.
Because Navier is very beautiful she can wear a lot of intricate jewelry stuff right? Well the trash wants to turn into Navier so she forces everyone to put a ton of jewelry on her that she looks like a Christmas tree on her wedding dress and even Soviesu thinks the same and the whole wedding Soviesu looks at Navier and remember their times together.
In Navier's wedding the trash tries to give back the sword Navier gave her but she couldn't do anything. The wedding night with Heinly is the thing you should wait for it's beautiful...and he is the bottoms then i just have to tell you we don't get too much action but it's very cute and satisfying.
Oh and Soviesu tries to get Navier back when Rashta tries to "Attract" nobles and does a ton of mistakes that Soviesu knows about and doesn't do anything about it so he can use it to divorce the trash, why? Because his plan was to divorce Navier recognize GlowyM the baby as his heir and as soon as possible to get back with Navier but obviously she doesn't want to and he even, later after she is pregnant with twins, he tries to becomes her concubine
Also the duke get revenge because his father had a concubine from the empire and his father left aside his sick mother for the concubine.
Something that happens with Rashta is that she tries to blame her servants of certain wrong doings, one that was nice with Soviesu got her tongue cut off because of rashta's orders and Soviesu knew.other one got thrown in jail because she attacked Rashta because she tried to get her family imprisoned and hanged. But at the end to loose Soviesu's trust she threw her baby to the floor because she remembered her first baby
Plot twist only Sovieshit have the side effect LMFAO, if Navier get pregnant with Heinley it will be clear that Trashta's baby is not Sovieshit's