I think they should get married because to me it has been very clear that Bell is only going to love Ais romantically. So it is absolutely pointless to have Lili try and win Bell over. When she knows she literally has no chance. That and to me Finn and Lili is probably one of the most sensible pairings in DanMachi. Both are brave Pallums, from famous Familias and both are good strategists with good leadership skills. It also help not only Finn's goal. It can also help Bell get closer to Ais. With Lili married to Finn. Then it will be one less girl of ruining Bell and Ais moments.
I think it could down a few ways. Tione wanting rip Lili's head off. With the others holding her back. Both Familias becoming allies. Due to members of their Familias being engaged. Or Finn leaving the Loki Familia.
So who else thinks Finn and Lili should become husband and wife with a child ?? How would it play out?