Hi, sorry, just wanna voice out my thoughts.
Bluberi, the house which your FH is staying in now, who pays for it? If it was being paid by your FMIL and your FH, I think they have the rights to keep the house under their names. Unless your FH is the only one who has been paying for the house, then you can request to put your name together with your FH.
I mean, can you imagine when you are old and you have this house where you have been staying for years, and all of a sudden you gotta give up the ownership to the FDIL even thou she's not paying for it? It doesn't sound fair, does it?
I guess your FMIL is also worried like you. What if one day you guys decided to desert her or something (just an example) then at least she still got the house right?
And I guess even if you have the house, it doesn't mean much of a security. It doesn't mean if you are the co-owner, your FH can't bring girls home. But, if you have always been paying for the house, the law will still give you back what's rightfully yours.
Guess if your FH die die dun want to get another house, just bear with it. Think of all the loans you wun have! =) In a few yrs time, when you have kids, your FH will eventually think the house is too small and propsoe to get a new one. So ganbate ne! =)